JPS6062542A - Air conditioning device - Google Patents

Abstract

PURPOSE:To make a controlling circuit compact and suppress the change and error of the rotational speed to low values by providing the frequency converter of a digital control type and the control device mainly consisting of a microcomputer thereby to change the rotational speed of a compressor responsive to the difference between a room temperature and a temperature set value. CONSTITUTION:A digital control type frequency converter 3 is connected to the control device 5 mainly consisting of a microcomputer. Output signals from a room temperature sensor 8, and a sensor 9 for sensing the condensing temperature and the evaporating temperature of coolant, are inputted to the control de- vice 5, and thereby to control the rotational speed of a compressor 4 responsive to the difference between the room temperature and a set temperature value set by a temperature setter. By this arrangement, the complicate control can be carried out by a simple circuit construction, and inconvenience accompanied by the weight of the load of a capacity variable type air conditioning device can be readily solved, and the change or error in the rotational speed of the compressor can be suppressed to low values.

Description

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

In order to maintain indoor air in the required state, the amount of heat that must be provided per unit time by air conditioning is called heating load, the amount of heat that must be removed is called cooling load, and the amount of humidity required for humidification or dehumidification is called air conditioning load. This air conditioning load can be roughly determined by measuring the difference between the room temperature and the temperature setting.

On the other hand, the heating and cooling capacity of an air conditioner can be varied over a wide range by fully controlling the rotation speed of the compressor.

Therefore, if the rotation speed of the compressor is changed based on the air conditioning load, the operating efficiency can be significantly increased, and it can also greatly contribute to energy saving.

In this way, the control system used a so-called linear circuit, which fully utilized voltage-frequency converters and other devices as a control device to change the rotation speed of the compressor based on the air conditioning load, so there were drawbacks such as overly complex circuits. there were. In addition, even when controlling in conjunction with room temperature, the frequency is set using an analog signal, so frequency fluctuations or errors are large.
It was not possible to fully demonstrate its function as a variable ability type.

The present invention has been made in view of the above points, and uses a digitally controlled frequency converter in the control device that changes the rotation speed of the compressor to divide the range of variation of the room temperature and temperature set point difference into multiple zones. To provide an air conditioner that has a configuration in which digital signals corresponding to each zone are added to the frequency converter, which simplifies the control circuit and suppresses fluctuations or errors in the rotational speed of the four machines. purpose.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of an air conditioner according to the present invention, in which the AC voltage of a power source 1 is converted to DC by a rectifier circuit 2, and the output frequency is changed to a range of about 25 to 80 Hz by adding it to a frequency converter #3. This allows the rotation speed of the compressor 4 to be changed to 14ON500rpm.
Varies within a range of m.

On the other hand, a digital signal applied to the frequency conversion device 3,
That is, the frequency setting signal is the output of the control device 5, and this control device 5 inputs the operation signal of the display operation section 6, the temperature data of the sensors 8 and 9, etc. to all microprocessors, and performs logic based on a preset program. Through calculation processing, the loads 7 such as four-way valves and fan motors are operated, and the frequency setting signal is sent to the frequency converter 3. At the same time, the operating status of the compressor 4 is displayed on the display (LEI) of the operation unit 6.
)).

Fig. 2 is a front view of the panel of the display/operation unit 6, where 11 is a bar display (LED) that displays the rotation speed of the compressor 4 as the full capacity level, If is a temperature setting device that sets the room temperature, and 13 is the intensity of the indoor fan. A selector switch that switches
] 4.15.16 is an operation stop switch that selects either cooling or heating for the air conditioner, or stops it altogether, 17.18L''!, an indicator (LED) that displays the operating status. Therefore, the display operation unit 6 outputs a setting signal for the temperature setting device 12, a fan intensity designation signal for the changeover switch 13, and an operation stop switch 14.1.
5.16 operation command signals are output, and all these signals are applied to the control device 5. At the same time, the control device 5 gives a signal to the display operation section 6 to turn on the par display 11 and the indicators 17 and 18. Next, the sensor 8 detects the room temperature, and the sensor 9 detects the condensation temperature or evaporation temperature of the refrigerant. is detected and limits the maximum frequency so that the pressure in the freezing cycle system does not exceed the allowable value.

Here, the control device 5 is mainly composed of a microcomputer (hereinafter referred to as microcomputer), and its control specifications correspond to the microcomputer program, so that complex control is possible. Therefore, the room temperature detected by the sensor 8,
A frequency setting signal corresponding to the difference from the temperature setting value of the temperature setting device 12 can be easily outputted, thereby making it possible to control the rotational speed of the compressor based on the air conditioning load.

Note that since a digital signal is applied to the frequency converter 3, it is possible to create a detailed correspondence between the room temperature and the temperature setting difference and the rotation speed of the compressor.
In this embodiment, all of this correspondence has been partially changed in consideration of the driving time factor.

Below, an example of the correspondence between the difference between room temperature and temperature setting value and the frequency setting signal will be shown.8. The entire operating state will be explained with reference to FIGS. 3 to 6.

First, as shown in Fig. 3, the range of variation in the difference between the room temperature and the temperature set point is determined separately in six zones A to F, depending on whether the room temperature is on a downward slope or on an upward slope.

I'm busy. That is, the entire A zone where the room temperature is higher than the temperature set value by lt or more in the downward slope region
The range 0.5~1.0℃ higher is the B zone, the range 0~05℃ higher is the C zone, and the range 0~0.5℃ lower than the temperature setting value? D zone, o, s ~1. o 'C low range i
The E zone is 1.0°C or more lower than the F zone. In addition, in the rising slope region Y, the kA zone is a range 1.5°C or more higher than the temperature set value, 1.0 to 15
℃ higher range is B zone, 0.5 to 10℃ higher range is C zone, 0 to 0.5b higher range 'tD zone, 0 to 0.5℃ lower than temperature set value = kE zone, 0.5 The range below ℃ is defined as the iF zone.

These temperature ranges and frequency setting signals are made to correspond as shown in the table. That is, 75Hz, 65Hz, and 1135Hz for zones A, B, --E, and F, respectively.
.

It corresponds to the situation of stopping.

If the difference between the temperature setting value and the temperature setting value is in the F zone, the change state of the room temperature expressed by the difference from the temperature setting value when the air conditioner is in full cooling operation based on such a correspondence relationship for the frequency converter 5, and The state of frequency change is shown in FIGS. 4(a) and 4(bl), respectively.

In the same figure, if the room temperature is in zone A where the difference between the room temperature and the temperature set value is 1.0 degrees or more, a 75Hz frequency setting signal is given, so the room temperature drops rapidly, and in zone B where the difference is 1.0 degrees Celsius or less. When the transition occurs, a 651-1z frequency setting signal is applied to the frequency conversion device, and thereafter, a 45HzO frequency setting signal is sequentially applied when the difference reaches the D zone. Note that as long as the room temperature is on the downward slope as described above and is maintained at 0 to 0.5 u lower than the temperature setting value, the 45 Hz frequency setting signal will continue to be output. After that, the room temperature rises and exceeds the temperature setting value by 0~05
Even if the temperature changes to a higher temperature, this range belongs to zone D in the rising slope of room temperature, so 458Z
17) Continue to output the full frequency setting signal. In other words, since there is a difference of 0.5 degrees between the zone setting where the room temperature is on a downward slope and the zone setting where the room temperature is on an upward slope, stiffness acts as hysteresis, so after the room temperature reaches the target value, the frequency setting value will not change frequently, and smooth operation will be achieved.

By the way, although the diagram of changes in room temperature and frequency setting shown in Figure 4 shows an example in which the air conditioning load is moderate and the room temperature steadily decreases, if the air conditioning load is relatively large, the room temperature will drop. It is also predicted that there will be a situation where the system has to operate at the same frequency for a long time even though the set temperature has not been reached. In order to solve all of these problems, in this embodiment, if the operation at the same frequency continues for 5 minutes, the difference between the room temperature and the temperature set value will become wider, and the 5F-1
Step 5 is taken to output frequency setting signals that differ by z. However, the A, B, and C zones will be increased by 5 Hz, and the D
, the F zone remains unchanged, and in the E zone, on the contrary, 5H
Reduce the number of balls. Is this an operating condition that takes into account not only the temperature element but also the time element? It is shown in FIG.

, so it is operated at a frequency of 75 Hz, and when the temperature difference shifts to zone B at this time T1, it is operated at a frequency of 65 Hz. However, from time T2, when the 65Hz 65Hz operation continued for 5 minutes, the frequency 58 increased to 70Hz.
drive with As a result, the rate of decrease in the room temperature becomes faster and the engine operates at a frequency of 60 Hz from time T3 when the temperature difference shifts to the C zone. Similarly, from time T4 when 601-1z continues to operate for 5 minutes, it operates at 65 Hz, and at time T, 2:551-12 when the temperature difference shifts to the D zone. In this way, even when the air conditioning load is large, the temperature can be quickly lowered to the set temperature.

Next, Figure 6 shows the operating state when the air conditioning load is light and cooling operation is performed, where (at is a diagram of changes in room temperature, (
bl is a frequency change state diagram.

In the same figure, even if the room temperature is in the D zone, which is lower than the set temperature, and the operation is performed at the set frequency of 45 Hz, at time T4, the room temperature drops to the E zone, which is lower than that, and the temperature is 35 Hz.
If the 8g operation continues for 5 minutes, the difference between the room temperature and temperature set point will be wider, and if the time that is maintained in the E zone even after turning is over 5 minutes, it will be even lower than this. Runs at 25H2. As a result, the engine operates at 351-1z from time 'I'7 when the room temperature rises and the difference between the room temperature and the temperature set value shifts to the D zone where the room temperature rises.

In this way, even when the load is light, the operating frequency f
Since the frequency is lowered in 5 Hz increments, it is possible to prevent the situation of overcooling.

Furthermore, since the program is controlled by a microcomputer, all control lines 5 can be performed while avoiding the resonant frequency of the piping.

As is clear from the above explanation, the air conditioner of the present invention is fully equipped with a digitally controlled frequency converter and a control device based entirely on a microcomputer, so that all complex control can be performed with a simple circuit configuration. This makes it possible to easily eliminate all problems associated with the light and heavy loads of the variable capacity air conditioner, and to extremely minimize fluctuations or errors in the rotational speed of the compressor.

[Brief explanation of drawings]

FIG. 1 is a front view of a panel of a display and operation section of an embodiment of an air conditioner according to the present invention, FIG. 3 is a diagram showing a state in which the temperature fluctuation range in the embodiment is divided into a plurality of zones, and FIGS. FIG. 6 is a diagram for explaining the operation of the same embodiment. DESCRIPTION OF SYMBOLS 1... Power supply, 2... Rectifier circuit, 3... Frequency converter 4... φ compressor, 5... Control device, 6... Display operation part 711, φ load, a9... sensor, 11--
- Bar display 12 - Temperature setting device. Representative Patent Attorney Kensuke Norichika Figure 1 Figure 2 Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] 1. A digitally controlled frequency converter that changes the rotation speed of a compressor by changing the frequency, and a control that provides a frequency setting signal to the frequency converter based on the difference between the room temperature and a temperature setting value. What is claimed is: 1. An air conditioner comprising: a device for controlling the rotation speed of a compressor according to a difference between a room temperature and a temperature setting value; 2. The air according to claim 1, which is provided with the control device, which divides the variation range of the difference between the room temperature and the temperature set value into a plurality of zones and outputs a frequency setting signal corresponding to each zone. harmonization device. 3. Divide the range of variation in room temperature and temperature setpoint difference into multiple zones, output a frequency setting signal corresponding to each zone, and detect when the operating time in the same zone exceeds the time setpoint. An air conditioner according to claim 1, wherein the control device is configured to output the full frequency setting signal.