JPH02279941A - Air-conditioner - Google Patents

Abstract

PURPOSE:To enable execution of a wide-range heating operation being excellent in an operation efficiency and free from noise or a signal by controlling a speed of rotation of a fan of an outdoor unit in accordance with a speed of reduction in the speed of rotation determined by calculating a rising speed of temperature, when a temperature based on a temperature signal is a second temperature or above which is lower than a first temperature, and by making changeover to a peak cut control when said temperature is the first temperature or above. CONSTITUTION:A microcomputer 11 of an indoor unit reads a refrigerant temperature detection signal from a thermistor T for detecting the high-pressure side temperature of a refrigerant and delivers the signal to a microcomputer 12 of an outdoor unit. When the high-pressure side temperature of the refrigerant based on the read temperature signal is a second temperature or above, the microcomputer 12 of the outdoor unit calculates a speed of change in the speed of rotation of a fan of the outdoor unit and others and controls the speed of rotation of a fan motor 14 of the outdoor unit. When the high-pressure side temperature of the refrigerant based on the temperature signal read in a control switching means is a first temperature or above which is higher than the second temperature, at least two of a heater, a fan of the indoor unit, a compressor and the fan of the outdoor unit are controlled sequentially and a peak cut control for lowering the high-pressure side pressure of the refrigerant is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to peak cut control during heating overload in an air conditioner.

<Prior Art> Conventionally, there are the following peak cut control methods for an air conditioner during heating overload.

That is, as shown in FIG. 4, when the high-pressure side pressure of the refrigerant reaches a predetermined pressure value HP as the outside air temperature rises, the auxiliary heater of the indoor heat exchanger is first turned off as a first step. Then, the high-pressure side pressure of the refrigerant decreases, allowing heating to continue.

However, when the outside temperature rises further and the high-pressure side pressure of the refrigerant reaches the predetermined pressure value HP again, the tap for the rotation speed of the fan of the indoor unit is switched to the high-speed side, and operation is continued to bring the high-pressure side pressure of the refrigerant to the predetermined value. When the pressure value HP is reached, the capacity of the compressor is controlled. Then, when the operation is continued and the pressure on the high pressure side of the refrigerant reaches the predetermined pressure value HP, the tap for the rotation speed of the fan of the outdoor unit is switched to the low speed side or stopped for the first time, and the operation is continued further and the high pressure side of the refrigerant When the pressure reaches a predetermined pressure value HP, the operation of the compressor is stopped. In this way, the rotation speed of the outdoor unit fan is kept constant while each part such as the auxiliary heater, indoor unit fan, and compressor is controlled in steps, so the compressor is stopped at relatively low outside temperatures. I ended up
There is a problem that the driving range is narrow. Therefore, at startup, if the outside air temperature is high, the time until the compressor stops is short, and the compressor repeatedly starts and stops.

Furthermore, in an inverter machine, the increase in the discharge pressure of the compressor is dealt with by keeping the rotational speed of the fan of the outdoor unit constant and controlling the frequency of the electric motor for the compressor. However, is it true that the electric motor for the compressor is driven at a low frequency? Therefore, when outdoor noise, vibration, etc. occur, the motor 2 is rotated again.

<Problems to be Solved by the Invention> However, "1. Among the two fan monitors that drive the two fans of the conventional outdoor unit, the rotation of one of the fan motors is stopped to perform peak cut control. In the harmonizer, when the high-pressure side pressure of the refrigerant reaches a predetermined pressure, the first fan motor 1 or the second fan motor 2 is simply activated depending on the rising speed of the high-pressure side pressure of the refrigerant.
However, since the air volume blown to the outdoor heat exchanger can only be controlled in two stages, there is a problem in that it is not possible to precisely deal with the rise in pressure on the high-pressure side of the refrigerant due to the rise in outside air temperature.

SUMMARY OF THE INVENTION Therefore, the purpose of this invention is to provide an air conditioner that is highly efficient in operation, free of noise and signals, capable of wide-range heating operation, and capable of performing detailed peak cut control against increases in the pressure on the high-pressure side of the refrigerant. Our goal is to provide the following.

<Means for Solving the Problems> In order to achieve the above object, this invention has the problem of poor annual energy efficiency as shown in FIG.

Therefore, an air conditioner has been proposed that copes with the increase in the pressure on the high-pressure side of the refrigerant by controlling the rotation speed of the fan in the outdoor unit.
Publication No. 18). The outdoor unit of this air conditioner has two fans, a first fan and a second fan. As shown in FIG. 5, during normal heating operation, the first fan motor contactor 3 and the second fan motor contactor 4 are excited, and the first fan motor 1 and the second fan motor 2 are driven.

When the pressure detector 5 detects that the high-pressure side pressure of the refrigerant has increased to the set pressure due to the rise in outside air temperature, the discrimination circuit 6 determines the rate of pressure increase and determines whether the rate of increase is greater than or equal to the set rate. In this case, the first fan motor 1 that drives the first fan with the larger air volume is stopped, and when the speed is less than the set speed, the second fan motor 2 that drives the second fan is stopped.

Then, when the discharge pressure of the compressor decreases again, the temperature on the high pressure side of the refrigerant is detected by the temperature detection means T, and the high pressure side temperature of the refrigerant is When the side temperature reaches a first temperature or higher, at least two of the heater, the indoor unit fan, the compressor, and the outdoor unit fan are sequentially controlled to perform peak cut control to lower the high-pressure side pressure of the refrigerant. reads the temperature signal from the temperature detection means T, and if the temperature based on the temperature signal is equal to or higher than the second temperature lower than the first temperature, the temperature increase rate is determined according to a predetermined rule. Based on the temperature increase rate calculated by the temperature increase rate calculation means and the temperature increase rate calculated by the temperature increase rate calculation means, the decrease rate of the rotation speed of the fan of the outdoor unit is determined, and the rotation speed decrease rate of the fan of the outdoor unit is determined according to the determined rotation speed decrease rate. fan rotation speed control means for controlling the rotation speed of the fan of the unit;
The present invention is characterized by comprising a control switching means that reads the temperature signal and switches to the peak cut control if the temperature based on the temperature signal is equal to or higher than the first temperature.

<Operation> The temperature signal from the temperature detection means T is read into the temperature increase rate calculation means, and if the high pressure side temperature of the refrigerant based on the read temperature signal is equal to or higher than the second temperature, the temperature is adjusted according to a predetermined rule. The climbing speed is calculated. Then, the fan rotation speed control means determines the speed of decrease in the rotation speed of the fan of the outdoor unit based on the temperature rise rate calculated by the temperature rise speed calculation means, and the outdoor unit according to the obtained rotation speed decrease speed. The rotation speed of the fan is controlled.

In this state, the temperature signal is read into the control switching means, and if the high-pressure side temperature of the refrigerant based on the read temperature signal is equal to or higher than the first temperature higher than the second temperature, the heater Peak cut control is performed by sequentially controlling at least two of the fan of the unit, the compressor, and the fan of the outdoor unit to lower the high-pressure side pressure of the refrigerant.

Therefore, before entering the peak cut control, the temperature Tc at which the rotation speed of the fan of the outdoor unit is linearly controlled at a rate of decrease corresponding to the rate of increase in the temperature on the high pressure side of the refrigerant is detected, and the temperature Tc is detected on the high pressure side of the detected refrigerant. It is determined whether the temperature Tc is equal to or higher than the first set temperature Tc. As a result, if the high pressure side temperature Tc of the refrigerant is equal to or higher than the second set temperature Tc+, the process proceeds to step S2.

In step S2, the rate of increase ΔTc of the high-pressure side temperature Tc of the refrigerant is calculated based on the conversion formula stored in the storage unit 13 shown in FIG.

In step S3, the rate of decrease in the rotational speed of the fan motor 14 is determined based on the table representing the relationship between the rate of increase ΔTc of the high-pressure side temperature Tc of the refrigerant and the rate of decrease in the rotational speed of the fan motor 14, which is stored in the storage unit 13. is determined, and the rotation speed of the fan motor I4 is decreased in accordance with the determined decreasing speed.

In step S4, the high pressure side temperature Tc of the refrigerant is detected based on the refrigerant temperature detection signal from the microcomputer 11 of the indoor unit, and the detected high pressure side temperature Tc of the refrigerant is higher than the second set temperature Tc. It is determined whether the temperature is equal to or higher than the first set temperature Tc7. As a result, if the temperature is higher than the first set temperature TC2, the step can be performed.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a block diagram of the rotation speed control of the fan of the outdoor unit according to the present invention. Indoor unit microcomputer 11
reads the refrigerant temperature detection signal from thermistor T for detecting the temperature on the high pressure side of the refrigerant and sends it to the microcomputer 12 of the outdoor unit.
Send to. Then, the microcomputer 12 of the outdoor unit
As will be described in detail later, the rotation speed of the fan motor 14 for the fan of the outdoor unit is controlled by calculating the speed of change in the rotation speed of the fan of the outdoor unit.

FIG. 2 is a flowchart of peak cut control performed in the microcomputer 12 of the outdoor unit during heating overload. Hereinafter, the peak cut control operation during heating overload will be explained in detail with reference to FIG.

In step S1, the process proceeds to the high pressure side S5 of the refrigerant based on the refrigerant temperature detection signal from the microcomputer 11 of the indoor unit, and if not, the process returns to step S1.

In step S5, the rotation speed of the fan motor I4 is set so that the air volume by the fan of the outdoor unit is minimized, and the auxiliary heater, the fan of the indoor unit, and the compressor are sequentially controlled to control the high-pressure side pressure of the refrigerant. It enters peak cut control to lower the temperature (hereinafter referred to as conventional peak cut control) and ends the peak cut control operation at the time of heating overload.

FIG. 3 is a diagram showing the relationship between the outside air temperature and the high-pressure side pressure of the refrigerant when the rotation speed of the fan motor I4 is controlled to perform peak cut control during heating overload according to the flowchart in FIG. 2. .

In FIG. 3, when the outside air temperature rises during heating, the pressure and temperature of the high-pressure side refrigerant rise. Then, when the outside air temperature reaches T, the high pressure side temperature of the refrigerant reaches the second set temperature Tc, and in steps 81 to S4 in FIG. The rotation speed of the fan motor 14 of the fan of the outdoor unit is linearly controlled and reduced according to the corresponding reduction speed. As a result, from the outside air temperature T1 to the outside air temperature T, the value of the high pressure side pressure of the refrigerant is approximately constant (HP, ).

Furthermore, when the outside air temperature rises to T, the pressure and temperature of the high-pressure side refrigerant rise again. Then, as described above, when the high pressure side temperature of the refrigerant reaches the first set temperature TC2 (at that time, the value of the high pressure side pressure of the refrigerant reaches HP2), the rotation of the fan motor 14 is stopped and the indoor unit The air volume of the fan is maintained at the minimum value, and the conventional peak cut control described above is entered.

In this way, in peak cut control during heating overload, before entering the conventional peak cut control, the high pressure side temperature Tc of the refrigerant is controlled by the microcomputer 12 of the outdoor unit.
The number of rotations of the fan motor 14 of the fan of the outdoor unit is decreased in accordance with the rising speed ΔTc of the fan. Therefore, the value of the high pressure side pressure of the refrigerant is changed to HP until the outside air temperature T3.
2 or less, enabling a wide range of heating operation until the conventional peak cut control is entered and the compressor is stopped. In addition, the microcomputer 12 of the outdoor unit linearly controls the rotation speed of the fan motor 14 according to the rate of increase ΔTc of the high-pressure side temperature Tc of the refrigerant. Cutting control can be performed.

Further, by performing the above-described control, the following effects are produced. In other words, 1. Before entering the conventional peak cut control, the rotation speed of the fan of the outdoor unit is controlled, so when the outside temperature exceeds T3 and the conventional peak cut control is entered, It is possible to reduce the discomfort caused by changes in draft feeling caused by turning off the auxiliary heater or changing the rotation speed of the indoor unit fan. In addition, when this invention is applied to an inverter machine, the frequency of the compressor motor can be maintained at a constant and efficient frequency until the outside temperature T5. It will also get better.

In the embodiment described above, when the rate of decrease in the rotational speed of the fan motor 14 to 11 is determined from the rate of increase ΔTc of the high-pressure side temperature Tc of the refrigerant, the rate of decrease in the rotational speed of the fan motor 14 is determined according to a table stored in the storage section J3.

However, the present invention is not limited to this, and a relational expression between the rate of increase ΔTc of the high-pressure side temperature Tc of the refrigerant and the rate of decrease in the rotational speed of the fan motor I4 is stored in the storage unit I3, and this relationship is stored in the storage unit I3. Fan motor 14 based on the formula
In the above embodiment, the rotation speed of the fan of the outdoor unit is controlled based on the rate of increase ΔTc of the high-pressure side temperature Tc of the refrigerant. The same effect can be obtained by controlling the rotation speed of the fan of the outdoor unit based on the rising speed of the outdoor unit. Therefore, the temperature detection means of the present invention includes those that detect temperature by detecting pressure, and those in which temperature rise is replaced with pressure rise are also included within the scope of this invention.

<Effects of the Invention> As is clear from the above, the air conditioner of the present invention is equipped with a temperature increase rate calculation means, a fan rotation speed control means, and a control switching means, and the temperature increase rate calculation means described in 1. If the high-pressure side temperature of the refrigerant based on the temperature signal from the detection means is equal to or higher than the second temperature, a temperature increase rate is calculated according to a predetermined rule, and the fan rotation speed control means calculates the temperature increase rate based on the calculated temperature increase rate. the rotation speed of the fan of the outdoor unit is controlled by determining the rate of decrease in the rotation speed of the fan of the outdoor unit, and the control switching means causes the high pressure side temperature of the refrigerant based on the temperature signal to be higher than the second temperature. If the temperature is above the first temperature, at least two of the heater, indoor unit fan, compressor, and outdoor unit fan are sequentially controlled to perform conventional peak cut control to lower the high pressure side pressure of the refrigerant. Therefore, before entering the conventional peak cut control described above, the rotation speed of the fan of the outdoor unit can be controlled to suppress an increase in the pressure on the high pressure side of the refrigerant. Therefore, the heating operation can be performed over a wide range of areas with good operating efficiency and no noise or vibration. In addition, the fan rotation speed control means linearly controls the rotation speed of the fan of the outdoor unit according to the rate of increase in the temperature on the high pressure side of the refrigerant, allowing for a new method of finely tuned peak cutting in response to increases in the pressure on the high pressure side of the refrigerant. Can be controlled.

[Brief explanation of drawings]

Fig. 1 is a block diagram of fan motor rotation speed control according to the present invention, Fig. 2 is a flowchart of peak cut control during heating overload, and Fig. 3 is a peak peak cut control during heating overload based on the flowchart of Fig. 2. Figure 4 is a diagram of the relationship between outside air temperature and refrigerant high pressure side pressure in cut control. Figure 4 is a diagram showing the relationship between outside air temperature and refrigerant high pressure side pressure in conventional peak cut control. Figure 5 is a diagram showing the relationship between outside air temperature and refrigerant high pressure side pressure in conventional peak cut control. (It is a block diagram of fan control. 11... Microcomputer of indoor unit, 12 Microcomputer of outdoor unit, I3 - Storage section, 14... Fan motor.

Claims (1)

[Claims] (1) When the temperature on the high pressure side of the refrigerant is detected by the temperature detection means (T) and the temperature on the high temperature side of the refrigerant exceeds the first temperature, the heater, indoor unit fan, compressor, and outdoor unit fan are activated. An air conditioner that performs peak cut control to lower the high pressure side pressure of the refrigerant by sequentially controlling at least two of them, the air conditioner reading a temperature signal from the temperature detection means (T),
If the temperature based on this temperature signal is equal to or higher than a second temperature lower than the first temperature, a temperature increase rate calculation means calculates the temperature increase rate according to a predetermined rule; A fan rotation speed control means that determines the speed of decrease in the rotation speed of the fan of the outdoor unit based on the temperature rise speed, and controls the rotation speed of the fan of the outdoor unit according to the determined rotation speed decrease speed; An air conditioner comprising control switching means that reads the temperature signal and switches to the peak cut control if the temperature based on the temperature signal is equal to or higher than the first temperature.