JPS5850189Y2 - Air conditioner control device - Google Patents

Description

[Detailed description of the invention] This invention automatically suppresses the total operating current of the air conditioner during heating operation to a range that is compatible with the power supply capacity, making it possible to maintain stable operation. The present invention relates to a control device for an air conditioner that can be used in both regions and achieve economical operation with an increased energy efficiency ratio.

When a heat pump air conditioner performs heating operation in extremely cold weather, the heating capacity is often insufficient, so an auxiliary electric heater is generally used. By using both, the operating current increases.

In this case, the capacity of the electric heater is limited by the set value of an automatic overload disconnector provided on the distribution line to which the compressor is connected.

In the case of a heat pump air conditioner for general household use, it is usually 2.
An automatic disconnector with a 0A rating is used, but in this case, for example, a refrigeration system whose electric heater capacity is determined so that it can be used with this automatic disconnector is subject to an increase in load, especially when the outside temperature increases. As a result, the compressor current increases rapidly, and as a result, the total operating current of the refrigeration equipment greatly exceeds the rated current of 20A, and the overcurrent cut-off mechanism with time-limiting characteristics in the automatic disconnector is activated, and the energization is released. Situations often occur in which the heating becomes inoperable.

This is because when selecting equipment, an outside temperature of 0°C is often used as a standard, but in reality, it is often operated at a temperature of 5 to 7°C.

Therefore, in order to continue operation as long as possible, it is necessary to keep the total operating current below the rated value.

As such a means, it may be possible to detect that the operating current is about to reach the rated current, turn off the electric heater, and continue the heating operation using only the refrigeration cycle, although the capacity may be slightly reduced.

If the load on the compressor becomes lighter due to a decrease in the refrigeration load or a drop in the outside temperature, the current decreases to a value that does not cause the automatic disconnector to open even if the electric heater is turned on. The electric heater should be turned on as soon as possible.

By the way, a general heat pump air conditioner is shared by two regions with different power frequencies of 50 Hz and 60 Hz, and the heating capacity of the heat pump refrigeration cycle is 50 Hz and 60 Hz.
It is well known that when used in a 0Hz area, the volume is slightly smaller, so it is installed in a room with a smaller heating load.Moreover, in a 50/60Hz dual-use model, the rated current value of the compressor, the height of the refrigeration cycle, etc. Since the operating characteristics such as pressure and the above-mentioned capacity are quite different, it is natural that if the overall operating current value is uniformly set to the same value for both regions, it will not be possible to achieve a satisfactory function.

For example, when setting the current value for automatic start/stop control based on the case of 60Hz, in the case of 50Hz, it is set for a room with a small heating load as described above, so there is surplus heating capacity in the heat pump refrigeration cycle operation. in spite of,
This resulted in the use of an auxiliary electric heater, which caused disadvantageous problems such as a decrease in the energy efficiency ratio (E, E, R) and uneconomical operation.

In view of the above-mentioned actual situation, the present invention was developed in an attempt to provide a control device that can fundamentally eliminate the disadvantages of conventional methods, and in particular suppresses the total operating current below an appropriate level. Therefore, when detecting this current value and automatically controlling the auxiliary electric heater on and off, the reference setting current is manually set in high power frequency areas and low power frequency areas so that the former is higher than the latter. It is characterized by a configuration that includes a switch that can be changed by operation.

It goes without saying that the compressor operating current and heating capacity of the heat pump refrigeration cycle in the former are both higher than those in the latter.

Aspects of the present invention will be explained in detail below with reference to one embodiment of the accompanying drawings.

Although the air conditioner according to the present invention is implemented, the main load is an electric motor for driving a compressor, and an electric heater, which is an auxiliary electric load with a smaller operating current than the electric motor, is used as the main load. They are provided as secondary loads, and are used by connecting them in parallel to a distribution line equipped with an automatic overload disconnector (hereinafter referred to as a breaker).

Then, compare the total operating current value with the set current value corresponding to the rated current of the breaker, and check whether the total operating current is
If the value reaches a value sufficient to activate the shutoff,
The slave load is turned off so that continuous refrigeration operation can be performed.

The control circuit for automatically starting and stopping the compressor motor and the electric heater is shown in FIG. It consists of a switch circuit (c) for turning on and off the electric heater, a total operating current detection circuit (ii), two-system comparison circuits (e) and (e), and a current setting switching circuit (t).

The switch circuit port has an electronic thermometer 1 for detecting room temperature and a relay 2 for a compressor motor (hereinafter referred to as "more relay 2") connected in series and inserted between the power supplies.

The switch circuit C includes an electric heater relay 3 (hereinafter referred to as heater relay 3) and a transistor 4 connected in series and inserted between the power sources.

Next, the full operating power supply detection circuit 2 has a current transformer 5 installed in the distribution line as an element, and is capable of generating a current proportional to the full operating current at the secondary terminal of the current transformer 5. It is formed into a well-known current transformation circuit.

Of the two comparison circuits E and E, the first comparison circuit E is connected to a resistor R.
1 and a capacitor C1 in series, a detection-side voltage divider circuit with resistors R2, R3, and R4 as elements, a setting-side voltage divider circuit with resistors R5, R6, and R7 as elements, and a comparator 9. The potential difference between the divided potential e1 of the capacitor C1 potential obtained by charging the time constant circuit 6 by the secondary current of the current transformer 5 and the reference potential e2 of the setting side voltage dividing circuit is The comparator 9 amplifies it to a high gain and outputs an L level output if el>e2, and an H level output if el<e2, so that the base potential of the transistor 4 can be regulated. It has become.

On the other hand, the second comparison circuit includes a transistor 10 that operates when the transistor 4 is off, and a transistor 10 that operates when the transistor 4 is off.
It consists of a capacitor C2 charged by the collector potential of , resistors R8 to R1□, and a comparator 11,
The potential difference between the charging level e3 of the capacitor C3 and the reference potential e4 is amplified to a high gain by the comparator 11, and the L level output is compared if e3>e4, and the H level output if e3<e4. The base potential of the transistor 4 can be regulated by outputting it from the circuit 11.

The current setting switching circuit has a single-pole single-throw switch 8 as an element, and this switch 8 is connected in parallel to the grounding resistor R4 in the detection-side voltage dividing circuit, and is operated in an open operation in a 50 m area and in a closed operation in a 60 Hz area. The level switching point of the comparator 9 can be changed by changing the level switching point of the comparator 9.

In FIG. 1, in the circuit in which transistor 12 and diode 13 are connected in series, transistor 12 is turned on when motor relay 2 is de-energized, and the output terminal of comparator 11 and the base of transistor 4 are connected. This is for forcibly shifting the line to L level.

The operation of the control circuit configured as described above will now be described.

When the room temperature reaches the set value and the motor relay 2 is de-energized, that is, when the heat pump refrigeration cycle is stopped, the base potential of the transistor 4 is regulated to the L level by turning on the transistor 12. Therefore, the electric heater is out of power due to the deenergization of the heater relay 3.

When the room temperature falls and the electronic thermostat 1 is activated, the motor relay 2 is energized, so the heat pump refrigeration cycle is operated.

At the same time, the off-regulation of the transistor 12 is lifted.

The total operating current is detected by the total operating current detection circuit 2,
The current generated on the secondary side of the current transformer charges the capacitor C1 with a predetermined time constant through the resistor R1, and the comparator 9
Apply a voltage proportional to the total operating current to the negative terminal of the

While this voltage e1 is smaller than the reference voltage e2, the comparator 9
Since the transistor 4 emits an H level output, the transistor 4 is turned on, the heater relay 3 is energized, and the electric heater is energized.

Conversely, when the voltage e1 increases, that is, when it reaches the set current value sufficient to trip the breaker, the comparator 9
The output becomes a low level, and as a result, the transistor 4 is turned off, the electric heater relay 3 is deenergized, and the electric heater is cut off, so that heating is performed only by the heat pump cycle.

Thus, when the electric heater is disconnected from the power supply, the total operating current is reduced and the output of comparator 9 is therefore at a high level.

Once the relay 3 is deenergized, the base potential of the transistor 10 becomes high and the transistor 10 is turned on, and the negative terminal input potential e3 of the comparator 11 becomes larger than the positive terminal input potential e4.

Therefore, the output of the comparator 11 becomes a low level and the transistor 4 is kept off, so that the loop 3 continues to be deactivated.

However, the charge in the capacitor C2 is discharged through the resistor R1□, and when a predetermined time corresponding to the discharge time constant is reached, the potential difference across the capacitor C2 decreases, and the comparator 1
The output of the comparator 11 becomes high level when the potential e3 of the negative terminal input of No. 1 decreases and finally becomes lower than the positive terminal input potential e4.

At this time, since the output of the comparator 9 is already at a high level, the resistor 4 is turned on, the relay 3 is energized, and the electric heater is energized.

Thus, the compressor motor and electric heater operate simultaneously, increasing the total operating current.

When the total operating current exceeds the above-mentioned OFF reference value due to the extent of this increase, the electric heater is de-energized again by the operation of the first comparison circuit E, but at this time, the current is detected by a time constant consisting of resistor R1 and capacitor C1. Because we are delaying the
The relay 3 continues to be energized for this charging time and then de-energized.

Thus, the electric heater is forcibly energized for the above-mentioned set time.

The above-mentioned operation is automatically repeated, and the peak load suppression and operation mode are shown in Figure 2 as the current hourly relationship (Figure A) and the electric heater operation time relationship (Figure 2). As shown, continuous refrigeration operation is possible through intermittent operation of the electric heater, and the refrigerating machine no longer stops due to opening of the breaker as in the past.

The set time period during which the electric heater is energized may be set to an allowable time that does not cause the breaker to open even if the total operating current is large, and breakers generally have a limited time characteristic or Since an overcurrent cutoff function with inverse time limit characteristics is provided, it is easy to set the charging time to an appropriate value based on the ratio of the off reference value to the rated current and the time limit characteristic of the breaker.

As is clear from the above operation description, the discharge time constant of the charging/discharging circuit consisting of capacitor C2 and resistors R8 to R1□ corresponds to the first time period for giving the switch circuit a predetermined time for turning on. However, on the other hand, the charging time constant of the charging circuit consisting of capacitor C1 and resistor R1 is
It goes without saying that the second time period for giving forced ON operation time to the switch circuit is limited to the time period that does not result in the opening operation of the switch circuit.

As mentioned above, heating operation is performed using a heat pump refrigeration cycle and an auxiliary electric heater, but in this case, while ensuring that the total operating current does not exceed the set value,
The heating operation using the heat pump refrigeration cycle is prioritized over the electric heater, and since there is a difference in the heating capacity of the heat pump refrigeration cycle between the 60+ frequency region and the 50+ frequency region, the heating load that is targeted in the former region is If the heating load is large, the switching device 8 is closed to effectively set the total operating current value to a high value. On the other hand, the current may be controlled according to the region of use by opening the valve and setting the total operating current value low.

For example, when the heating capacity of a 100cm room air conditioner is 3150 Kcal/h, 50 Hz (50 Hz) when the fluorocarbon heater is operated at an outside temperature of 7°C or less, the heating capacity is 60°.
7) The case has a capacity of 2800 Kcal/h, compressor electric motor output cuff 50W, Freon heater input cuff 00W
With the standard specifications of
．． 6A), 50I (16.5A (ON setting value is 15.5A) for Z), resistors R2 and R
3. After determining each value of R4 and conducting actual measurements, we found that in any frequency region, when the outside air temperature is below 4.5°, the electric heater is continuously energized and heating operation is possible without causing a drop in room temperature. On the other hand, under conditions where the outside air temperature was 4.5° or higher, operation was achieved in which the electric heater was efficiently used as an auxiliary heat source while the total operating current value was regulated to the set value.

That is, it has been proven that when a model is selected based on the outside temperature of 0° C. as described above, it is convenient when the outside air temperature is 4.5° C. without insufficient heating capacity.

Furthermore, under conditions where the outside air temperature rises and the compressor is nearly at full load, the electric heater almost never goes into operation, making it possible to automatically perform highly energy-efficient operation.

As is clear from the above description, the present invention allows the set value of the total operating current detected by the current detector 5 to be set at 60 Hz and 50 Hz.
Hz, and the auxiliary heating electric heater is automatically turned on and off to ensure that the set value is not exceeded, so in both regions with different power supply frequencies,
It becomes possible to satisfactorily perform both functions of suppressing the current capacity on the power supply side to an appropriate value and also turning off the electric heater at a certain load, allowing the air conditioner to be used efficiently and economically.

Note that the current transformer 5 is configured to detect only the current that does not include the current of the auxiliary electric heater, that is, substantially only the compressor current of the heat pump refrigeration cycle, without using the entire operating current detection circuit 2 (at this time, the The value can be set lower by the amount equivalent to the heater current value), and it can be done simply by switching the switch 8, so it is convenient in handling and is ideal for practical equipment. The present invention is an air conditioner control device that has various excellent effects, such as eliminating the trouble of making adjustments depending on the region of use and streamlining the service.

[Brief explanation of the drawing]

Fig. 1 shows an electric circuit according to an example of the device of the present invention, and Fig. 2 A and 2 show a total operating current one-hour relationship diagram and an auxiliary electric load operation one-hour relationship diagram showing the operating characteristics of the circuit shown in the first country. be. 5...Current detector, 8...Switcher, Port...Compressor motor switch circuit, C...
...Electric heater switch circuit, 2...Full operating current detection circuit, E, H...Comparison circuit, G...
...Current setting switching circuit.

Claims (1)

[Scope of utility model registration request] The current detector 5 is shared by two regions with different power supply frequencies.
The compressor of the heat pump refrigeration cycle is controlled by a current control circuit that compares the total operating current value detected by the set current value with the set current value and automatically controls the start/stop of the auxiliary heating electric heater so that the former does not become larger than the latter. In an air conditioner that is operated with priority over an electric heater, a switch 8 that can manually convert the set current in a high power frequency region and a low power frequency region so that the former is higher than the latter. A control device for an air conditioner, characterized in that the current control circuit is provided with: