JP3232755B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner capable of performing a heating operation, and more particularly to control of an air flow rate of a heat source side fan.

[0002]

2. Description of the Related Art In general, for example, in an air conditioner, as disclosed in Japanese Utility Model Publication No. 52-39238,
A compressor, a four-way switching valve, an outdoor heat exchanger having an outdoor fan, an electric expansion valve for cooling, an electric expansion valve for heating, and an indoor heat exchanger having an indoor fan are sequentially connected so as to be capable of reversible operation. In some cases, a refrigerant circulation circuit is formed.

When the outside air temperature is detected and the outside air temperature rises during the cooling operation cycle, the air flow of the outdoor fan is rotated at a high speed. On the other hand, when the outside air temperature rises during the heating operation cycle, the air flow of the outdoor fan is rotated at a low speed. In addition, the pressure of the high-pressure refrigerant is prevented from rising.

[0004]

In the above-described air conditioner, the air flow rate of the outdoor fan is controlled only by the outside air temperature, and the pressure state of the low-pressure refrigerant is not considered at all.
There was a problem that the reliability of the compressor was low.

That is, for example, when the outside air temperature is high during the heating operation cycle, the high-pressure refrigerant pressure is high.
The air volume of the outdoor fan is sequentially reduced for each sampling time. In this case, it is possible to prevent the increase in the high-pressure refrigerant pressure.However, the air flow of the outdoor fan is reduced more than necessary, and the low-pressure refrigerant pressure is excessively reduced, which may cause the compressor to perform wet operation. On the contrary, there is a problem that the load on the compressor is increased and the reliability is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to improve the reliability of a compressor by preventing the air flow of a heat source side fan from unnecessarily decreasing.

[0007]

Means for Solving the Problems In order to achieve the above-mentioned object, a means taken by the present invention is to control the air flow rate of the heat source side fan in consideration of the saturation temperature corresponding to the evaporating pressure during the heating operation cycle. It was done.

More specifically, as shown in FIG. 1, means taken by the invention according to claim 1 firstly includes a compressor (21) and a heat source side heat exchanger () having a heat source side fan (26). 23) and the expansion mechanism (2
5) and a use-side heat exchanger (31) are connected in order to provide a refrigerant circulation circuit (1) capable of performing a heating operation. And an air volume adjusting means (72) for adjusting the air volume by switching the air volume of the heat source side fan (26) to a plurality of stages, and the heat source side heat exchanger (23)
Evaporation temperature detection means for detecting the evaporation pressure corresponding saturation temperature (Thc), a high pressure detection means (HPS2) for detecting a condensation temperature corresponding saturation pressure at the top Symbol refrigerant circuit (1) and is provided in
ing. Further, a pressure discriminating means for taking in the pressure signal of the high pressure detecting means (HPS2) and outputting a high pressure signal when the detected pressure is equal to or higher than the set pressure and outputting a low pressure signal when the detected pressure is lower than the set pressure at predetermined time intervals. 73) is provided. In addition
Then, take in the temperature signal of the evaporation temperature detecting means (Thc),
Each time the pressure discriminating means (73) outputs a high pressure signal, the air volume adjusting means (72) outputs a decrease signal for sequentially decreasing the air volume of the heat source side fan (26) so that the air volume becomes a low air volume corresponding to the evaporating pressure equivalent saturation temperature. ), And every time the pressure discriminating means (73) outputs a low pressure signal, an increasing signal for sequentially increasing the air volume of the heat source side fan (26) so as to have a high air volume corresponding to the evaporating pressure equivalent saturation temperature is output. An air volume control means (75) for outputting to the air volume adjustment means (72) is provided.

Further, the means taken by the invention according to claim 2 is that a heat source provided with a compressor (21) and a heat source side fan (26) is first provided.
Source side heat exchanger (23), expansion mechanism (25), user side heat exchanger
(31) are connected in order and a refrigerant circulation circuit capable of heating operation
(1) is provided. And the heat source side fan (26)
Air volume adjusting means for adjusting the air volume by switching the air volume to multiple stages
Stage (72) and the evaporation pressure phase in the heat source side heat exchanger (23)
Evaporating temperature detecting means (Thc) for detecting the saturation temperature;
Detects saturation pressure equivalent to condensation temperature in refrigerant circuit (1)
High-pressure detection means (HPS2) to detect the outside air temperature
Pressure signal of the detecting means (Tha) and the high pressure detecting means (HPS2)
High pressure signal when the detected pressure is higher than the set pressure.
If the detected pressure is lower than the set pressure,
Pressure discriminating means (73) for outputting at predetermined time intervals, and the outside air temperature
The temperature signal of the detection means (Tha) is taken in, and the detected outside air temperature is set.
If the temperature is higher than the predetermined temperature, a high temperature signal is
If the temperature is lower than the specified temperature, a low-temperature signal is output every predetermined time
Outside temperature determining means (74) is provided. Then, the temperature signal of the evaporating temperature detecting means (Thc) is fetched, and each time the pressure determining means (73) outputs the high pressure signal, the outside air temperature determining means (7
Outputting a decrease signal for sequentially decreasing the air volume of the heat source side fan (26) to a low air volume corresponding to the evaporating pressure equivalent saturation temperature based on the high temperature signal and the low temperature signal of 4) to the air volume adjusting means (72), Each time the pressure discriminating means (73) outputs a low pressure signal, the heat source side fan (26) is controlled so as to have a high air volume corresponding to the evaporating pressure equivalent saturation temperature based on the high temperature signal and the low temperature signal of the outside air temperature discriminating means (74). air volume control means for the increase signal for sequentially increasing the air volume is outputted to the air volume adjusting means (72) (75) is provided for).

A third aspect of the present invention is to provide a heat pump provided with a compressor (21) and a heat source side fan (26).
Source side heat exchanger (23), expansion mechanism (25), user side heat exchanger
(31) are connected in order and a refrigerant circulation circuit capable of heating operation
(1) Switch the air volume of the heat source side fan (26) to multiple stages
Air volume adjusting means (72) for adjusting the air volume.
You. Then, a high-pressure detecting means (HPS2) for detecting a condensing temperature equivalent saturated pressure in the refrigerant circuit (1) and a pressure signal of the high-pressure detecting means (HPS2) are taken in at each sampling time, and the detected pressure is higher than a set pressure. When there is a heat source side fan (26)
Air flow control means (76) for outputting a decrease signal for reducing the air flow of the air flow control means (72) to the air flow control means (72), respectively, when the detected pressure is lower than the set pressure, an increase signal for increasing the air flow of the heat source side fan (26). When the air volume control unit (76) outputs the decrease signal and the increase signal, the air volume holding unit (77) stops the output of the air volume control unit (76) until the standby time corresponding to the decrease signal and the increase signal elapses. ) are provided.

[0011]

According to the above construction, according to the first aspect of the present invention,
First, during the heating operation, the high-pressure refrigerant discharged from the compressor (21) is condensed and liquefied in the use-side heat exchanger (31), and the liquid refrigerant is decompressed by the electric expansion valve (25). After that, a circulation returns to the compressor (21) after evaporating in the heat source side heat exchanger (23).

[0012] Then, during the heating operation, the evaporation pressure corresponding saturation temperature evaporation temperature detection means (Thc) is in the heat source-side heat exchanger (23), i.e., the co detects the evaporation temperature,
High pressure detecting means (HPS2) condensation temperature corresponding saturation pressure, i.e.,
High pressure refrigerant pressure is detected. In the invention according to claim 2 , the high-pressure refrigerant pressure is detected, and the outside air temperature detection method is performed.
The stage (Tha) detects the outside air temperature .

[0013] Further, the pressure determining means (73) takes in the pressure signal of the pressure detection means (HPS2), a high-pressure signal when there in detected pressure set pressure or more, the detected pressure is lower than the set pressure low Signals are output at predetermined time intervals. Then, the air volume control means (75) takes in the temperature signal of the evaporating temperature detection means (Thc) so that each time the pressure discriminating means (73) outputs a high pressure signal, a low air volume corresponding to the evaporation temperature is obtained. A lowering signal for sequentially reducing the air volume of the heat source side fan (26) is output to the air volume adjusting means (72), and each time the pressure discriminating means (73) outputs a low pressure signal, the air volume is increased to a high air volume corresponding to the evaporation temperature. An increase signal for sequentially increasing the air volume of the heat source side fan (26) is output to the air volume adjusting means (72). As a result, the heat source
The pressure of the high-pressure refrigerant
Prevent pressure build-up.

[0014] In the invention of claim 2 , the outside air temperature detection is performed.
Takes in the temperature signal of the output means (Tha) and sets the detected outside air temperature
If the temperature is higher than the specified temperature, a high temperature signal is output.
If the temperature is lower, a low-temperature signal is output every predetermined time.
Then, the air volume control means (75) is connected to the evaporation temperature detection means (T
hc), and every time the pressure discriminating means (73) outputs a high-pressure signal, the heat source is set so as to have a low air volume corresponding to the evaporation temperature based on the high temperature signal and the low temperature signal of the outside air temperature discriminating means (74). A decrease signal for sequentially decreasing the air volume of the side fan (26) is output to the air volume adjusting means (72), and the pressure discriminating means (7
3) Each time the low pressure signal is output, the air flow of the heat source side fan (26) is sequentially increased so that the air flow becomes high corresponding to the evaporation temperature based on the high temperature signal and the low temperature signal of the outside air temperature determination means (74). A signal is output to the air volume adjusting means (72) to prevent an increase in the high-pressure refrigerant pressure.

Further, in the invention according to claim 3, during the heating operation, the air volume control means (76) is provided with the high pressure detection means (HPS2).
Signal at each sampling time.If the detected pressure is equal to or higher than the set pressure, a decrease signal that decreases the air volume of the heat source side fan (26) is obtained.If the detected pressure is lower than the set pressure, the air volume of the heat source side fan (26) is reduced. Are output to the air volume adjusting means (72). When the air volume control means (76) outputs the decrease signal and the increase signal, the air volume holding means (77) updates the air volume control means (76) until the standby time corresponding to the decrease signal and the increase signal elapses. Will be stopped. As a result, the air volume of the heat source side fan (26) is prevented from being excessively reduced, and hunting of the air volume change is prevented.

[0016]

According to the first aspect of the present invention, when the outside air temperature or the saturation pressure equivalent to the condensing pressure becomes larger than a predetermined value, the air volume of the heat source side fan (26) is reduced to a low air volume corresponding to the saturation temperature equivalent to the evaporation pressure. Therefore, it is possible to prevent the high-pressure refrigerant pressure from rising, and at the same time, prevent the low-pressure refrigerant pressure from excessively lowering, thereby preventing the heat source side heat exchanger (23) from freezing, and Wet operation can be prevented. As a result, it is possible to prevent the compressor from being overloaded, thereby improving reliability.

According to the second aspect of the present invention, when the condensing pressure-equivalent saturation pressure reaches a predetermined value, the heat source side fan (26) has a low air flow corresponding to the evaporation pressure-equivalent saturation temperature based on the outside air temperature.
Is set, it is possible to more reliably prevent the low-pressure refrigerant pressure from excessively lowering, and to further improve the reliability of the compressor.

According to the third aspect of the present invention, when the air volume of the heat source side fan (26) changes, the air volume does not change for a predetermined period of time. It is possible to prevent the user from doing too much.
Furthermore, since hunting of a change in air volume can be prevented, comfort can be improved, and load fluctuation of the compressor can be suppressed, and reliability can be improved.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 2 shows a refrigerant piping system in the air conditioner according to the second aspect of the present invention. (1) is a refrigerant circulation circuit, and one outdoor unit (2) is provided for one outdoor unit (2). It is configured as a so-called separate type to which the indoor unit (3) is connected.

The outdoor unit (2) includes a scroll type compressor (21) whose operating frequency is variably adjusted by an inverter, and a cutoff as shown by a solid line in the cooling operation and a broken line in the heating operation. Replacement Four Way Switching Valve (22)
And an outdoor heat exchanger (23) that is a heat source side heat exchanger that functions as a condenser during cooling operation and as an evaporator during heating operation.
An auxiliary heat exchanger (24) of the outdoor heat exchanger (23), an electric expansion valve (25) that is an expansion mechanism for reducing the pressure of the refrigerant, and a refrigerant regulator (4). , The outdoor heat exchanger (2
An outdoor fan (26), which is a heat source side fan, is arranged near 3). On the other hand, the indoor unit (3) is provided with an indoor heat exchanger (31), which is a use side heat exchanger that functions as an evaporator during the cooling operation and as a condenser during the heating operation. The indoor fan (3
2) is located.

The compressor (21) and the four-way switching valve (22)
And outdoor heat exchanger (23), auxiliary heat exchanger (24) and electric expansion valve (2
5), a refrigerant regulator (4) and an indoor heat exchanger (31) are connected in order by a refrigerant pipe (11), and the refrigerant circulation circuit (1) cools down so as to generate heat transfer by circulation of the refrigerant. The closed circuit is capable of reversible operation between an operation cycle and a heating operation cycle.

Further, the refrigerant circuit (1) is configured by arranging the electric expansion valve (25) so that the refrigerant flows in both directions. That is, the electric expansion valve (25) is provided with a cooling operation cycle. The refrigerant flows in different directions between the heating operation cycle and the heating operation cycle to reduce the pressure (solid line in FIG. 2 indicates cooling, and broken line indicates heating). Further, the refrigerant circulation circuit (1) is configured as a chargeless circuit without an accumulator, and heats at one end of the indoor heat exchanger (31), specifically, at the refrigerant outlet side during a cooling operation cycle. The inlet side of the refrigerant during the operation cycle is directly connected to the compressor (21) via the four-way switching valve (22).

On the other hand, the refrigerant regulator (4) is interposed in a refrigerant pipe (11) that becomes a low-pressure liquid line during a cooling operation cycle and becomes a high-pressure liquid line during a heating operation cycle, and is formed to be able to store liquid refrigerant. ing. And the refrigerant controller (4)
Is configured to adjust the amount of circulating refrigerant during a cooling operation cycle and store excess refrigerant during a heating operation cycle.

In FIG. 2, (F1 to F3) are filters for removing dust in the refrigerant, and (ER) is a silencer for reducing the operation noise of the compressor (21).

Further, sensors are provided in the air conditioner, and a discharge pipe sensor (Thd) for detecting a discharge pipe temperature Td is disposed in a discharge pipe of the compressor (21). At the air suction port of the unit (2), an outside air temperature sensor (Tha) which is an outside air temperature detecting means for detecting an outside air temperature Ta which is an outside air temperature is arranged, and the outdoor heat exchanger (23) has a cooling unit. An outdoor heat exchange sensor (Thc), which is an evaporating temperature detecting means for detecting an outdoor heat exchange temperature Tc that becomes a condensing temperature during operation and becomes an evaporating temperature (saturated temperature corresponding to evaporating pressure) during heating operation, is arranged. A room temperature sensor (Thr) that detects the indoor air temperature Tr, which is the indoor temperature, is disposed at the air suction port of () .The indoor heat exchanger (31) has an evaporation temperature during cooling operation and condenses during heating operation. Indoor heat exchange temperature
An indoor heat exchange sensor (The) for detecting Te is arranged.
Further, in the discharge pipe of the compressor (21), a high-pressure protection pressure switch (HPS1) that detects a high-pressure refrigerant pressure HP and is turned on by a rise in the high-pressure refrigerant pressure HP to output a high-pressure protection signal.
And a high-pressure control pressure switch (HPS) which is a high-pressure detection means for detecting the high-pressure refrigerant pressure HP (saturation pressure corresponding to the condensing temperature) and outputting an ON signal when the high-pressure refrigerant pressure HP reaches a predetermined value.
2) and a low-pressure protection pressure switch that detects a low-pressure refrigerant pressure in the suction pipe of the compressor (21) and turns on to output a low-pressure protection signal when the low-pressure refrigerant pressure drops excessively.
(LPS1).

The output signals of the sensors (Thd,..., The) and the switches (HPS1, HPS2, LPS1) are sent to the controller.
(7), the controller (7) is configured to control the air-conditioning operation based on the input signal,
(21) capacity control means (71), air volume adjustment means (72), pressure determination means (73), outside air temperature determination means (74), air volume control means
(75).

The capacity control means (71) changes the operating frequency of the inverter from zero to the maximum frequency by 20 steps N
In addition, for example, the optimum value Tk of the discharge pipe temperature Td that gives an optimum refrigeration effect from the condensation temperature or the evaporation temperature detected by the outdoor heat exchange sensor (Thc) is calculated, and the discharge pipe temperature Td is set to the optimum value Tk. Is set so as to control the capacity of the compressor (21) by setting the frequency step N so that the discharge pipe temperature is controlled.

The air volume adjusting means (72) adjusts the air volume of the outdoor fan (26) to a plurality of stages, for example, from HH of the maximum air volume to H
And the air flow rate is adjusted by switching to four stages of a low air flow rate of L and an OFF stop state.

The pressure discriminating means (73) takes in the pressure signal of the high pressure control pressure switch (HPS2), and outputs the high pressure signal when the detected pressure is equal to or higher than a set pressure (for example, 24 kg / cm ² ). If the pressure is lower than a set pressure (for example, 24 kg / cm ² ), a low pressure signal is output at each predetermined time.

The outside air temperature determining means (74) takes in the temperature signal of the outside air temperature sensor (Tha), and outputs a high temperature signal when the detected outside air temperature is higher than a set temperature (for example, 15 ° C. or 2 ° C.). If the detected outside air temperature is equal to the set temperature (for example, 15 ° C. or 2
If the temperature is lower than (° C), a low-temperature signal is output at predetermined time intervals.

The air volume control means (75) takes in the temperature signal of the outdoor heat exchange sensor (Thc), and every time the pressure determination means (73) outputs a high pressure signal, the outside air temperature determination means (74) A lowering signal for sequentially reducing the airflow of the outdoor fan (26) so as to have a lower airflow corresponding to the outdoor heat exchange temperature Tc based on the high temperature signal and the low temperature signal is output to the air volume adjusting means (72), and the pressure discrimination is performed. Each time the means (73) outputs a low pressure signal, the air flow rate of the outdoor fan (26) is adjusted so that the air flow rate becomes high corresponding to the outdoor heat exchange temperature Tc based on the high temperature signal and the low temperature signal of the outside air temperature determination means (74). The increase signal for sequentially increasing the air flow amount adjusting means (72)
Output to

Next, the cooling and heating operation of the above-described air conditioner will be described.

First, in the refrigerant circuit (1), during the cooling operation cycle, the high-pressure refrigerant discharged from the compressor (21) is condensed and liquefied in the outdoor heat exchanger (23), and this liquid refrigerant is After the pressure is reduced by the electric expansion valve (25), the refrigerant controller (4)
And then evaporates in the indoor heat exchanger (31) to
The circulation returns to (21). On the other hand, during the heating operation cycle, the high-pressure refrigerant discharged from the compressor (21) is condensed and liquefied in the indoor heat exchanger (31), and this liquid refrigerant is
After flowing into (4), the pressure is reduced by the electric expansion valve (25), and then
The circulation evaporates in the outdoor heat exchanger (23) and returns to the compressor (21).

In each of the operation cycles, the capacity control means (71) determines the optimum value Tk of the discharge pipe temperature Td which gives an optimum refrigerating effect from the condensation temperature or the evaporation temperature detected by the outdoor heat exchange sensor (Thc). Calculated, the frequency step N is set so that the discharge pipe temperature Td becomes the optimum value Tk, the capacity of the compressor (21) is controlled, and the air conditioning operation corresponding to the indoor load is performed.

Next, the control of the air flow rate of the outdoor fan (26) during the heating operation cycle will be described with reference to FIGS.

First, when the control of the outdoor fan (26) is started, in step ST1, the air volume control means (75) sends the high pressure signal based on the ON signal of the high pressure control pressure switch (HPS2). It is determined whether or not the output has been performed, and when a high-pressure signal is output, the determination is yes and the process proceeds to step ST2, where the outside temperature determination means (74) outputs a high temperature signal based on the temperature signal of the outside temperature sensor (Tha). It is determined whether or not.

When the outside air temperature Ta is equal to or higher than 15 ° C., the outside air temperature determination means (74) outputs a high temperature signal.
The process moves from step ST2 to step ST3.
If Ta is less than 15 ° C., a low-temperature signal is output, so that the process moves from step ST2 to step ST4.

Thereafter, in step ST3, the temperature signal of the outdoor heat exchange sensor (Thc) is received to determine whether or not the outdoor heat exchange temperature Tc, which is the evaporation temperature, is 5 ° C. or more. The process moves from step ST3 to step ST5, and
If it is not less than ° C., the process moves from step ST3 to step ST6.

Subsequently, in step ST5, the air volume control means (75) outputs a signal for reducing the air volume, and the air volume control means (72) receives this reduction signal, and the air volume control means (72) If the fan (26) is currently at the highest air flow HH, the air flow is set to H at the medium air flow. Also, the above step ST
In 6, the air volume control means (75) outputs a signal for reducing the air volume, and the air volume control means (72) receives the reduced signal, and the air volume control means (72) outputs the current maximum air volume to the outdoor fan (26). HH
If it is, the medium air volume is set to H. If the current medium air volume is H, the air volume is set to L for low air volume. .

On the other hand, in step ST4, it is determined whether or not the outdoor heat exchange temperature Tc, which is the evaporation temperature, is equal to or higher than 0 ° C. based on the temperature signal of the outdoor heat exchange sensor (Thc). Move from step ST4 to step ST7,
If so, the process moves from step ST4 to step ST8.

Subsequently, in step ST7, the air volume control means (75) outputs a signal for reducing the air volume, and the air volume control means (72) receives the reduction signal, and the air volume control means (72) If the fan (26) is currently at the HH with the highest air volume, it is set to H at the middle air volume and returns. Further, in the above step ST8, the air volume control means (75) outputs an air volume reduction signal, and the air volume adjustment means (72) receives this reduction signal,
If the outdoor fan (26) is currently at the highest air volume HH, the air volume adjusting means (72) will set the medium air volume to H and the current medium air volume to H.
If so, the flow is set to L with a low air flow and the routine returns.

That is, for example, in step ST6, since the outdoor heat exchange temperature Tc is 5 ° C. or higher, freezing does not occur even when the outdoor fan (26) is stopped. Therefore, the minimum air volume to be reduced in the temperature state of each outdoor heat exchange temperature Tc is set.

On the other hand, in step ST1, when the pressure discriminating means (73) outputs a low pressure signal, the air volume control means (75) makes a negative decision and proceeds to step ST9, where the outside air temperature discriminating means (74) Determines whether a high temperature signal has been output based on the temperature signal of the outside air temperature sensor (Tha).

When the outside air temperature Ta is 2 ° C. or higher, the outside air temperature determination means (74) outputs a high-temperature signal, so that the routine proceeds from step ST9 to step ST10.
Is less than 2 ° C., a low-temperature signal is output, so that the process moves from step ST9 to step ST11.

Thereafter, in step ST10, the temperature signal of the outdoor heat exchange sensor (Thc) is received, and it is determined whether or not the outdoor heat exchange temperature Tc, which is the evaporation temperature, is -5 ° C or higher, and is lower than -5 ° C. The process proceeds from step ST10 to step ST12, and if the temperature is -5 ° C. or more, the process proceeds from step ST10 to step ST12.
It will move to 13.

Subsequently, in step ST12, the air volume control means (75) outputs an air volume increase signal, and the air volume control means (72) receives the increase signal, and the air volume control means (72) If the fan (26) is currently in the OFF state of the stopped state, the flow is set to L with a low air flow, and if the fan is currently at a low air flow, the air is set to H with a medium air flow and the routine returns. Also, the above steps
In ST13, the air volume control unit (75) outputs an air volume increase signal, and the air volume adjustment unit (72) receives the increase signal, and the air volume adjustment unit (72) is in a state where the outdoor fan (26) is currently stopped. O
If it is FF, it will be set to L with a low air flow and return.

On the other hand, in step ST11, it is determined whether or not the outdoor heat exchange temperature Tc, which is the evaporation temperature, is equal to or higher than -10.degree. C. by receiving the temperature signal from the outdoor heat exchange sensor (Thc). Then, the process proceeds from step ST11 to step ST14.
It will move to ST15.

Subsequently, in step ST14, the air volume control means (75) outputs an air volume increase signal, and the air volume control means (72) receives the increase signal, and the air volume control means (72) If the fan (26) is currently in the OFF state of the stopped state, it is set to L at a low air volume, and if it is currently at a low air volume, it is set to H at a medium air volume.
If the current air volume is H, the program returns to the highest air volume HH. Also, the above steps
In ST15, the air volume control unit (75) outputs an air volume increase signal, and the air volume adjustment unit (72) receives the increase signal, and the air volume adjustment unit (72) is in a state where the outdoor fan (26) is currently stopped. O
If it is FF, it is set to L of low air flow, and if it is L of low air flow at present, it is set to H of medium air flow and returns.

That is, the maximum air volume to be increased in each outdoor heat exchange temperature Tc is set.

Therefore, according to this embodiment, when the outside air temperature Ta and the high-pressure refrigerant pressure HP become larger than the predetermined values, the air flow of the outdoor fan (26) is reduced to a low air flow corresponding to the outdoor heat exchange temperature Tc. It is possible to prevent the refrigerant pressure HP from rising, and at the same time, prevent the low-pressure refrigerant pressure from dropping too much, prevent the outdoor heat exchanger (23) from freezing, and perform the wet operation of the compressor (21). Can be prevented. As a result, the compressor (21) can be prevented from being overloaded, so that reliability can be improved.

In particular, when the high-pressure refrigerant pressure HP reaches a predetermined value,
Since the outdoor fan (26) is set to a low air flow corresponding to the outdoor heat exchange temperature Tc based on the outdoor air temperature Ta, it is possible to more reliably prevent the low-pressure refrigerant pressure from excessively decreasing, and to prevent the compressor (2
As possible out to improve the reliability of the 1).

Although not shown, as an embodiment of the first aspect of the present invention, the high-pressure refrigerant pressure HP and the outdoor heat exchange temperature Tc
Thus, the air volume of the outdoor fan (26) may be controlled.

That is, at the outside air temperature Ta, the air volume of the outdoor fan (26) is not controlled, and the high-pressure refrigerant pressure HP becomes, for example, 24 kg /
When the pressure is equal to or more than cm ^{2, the process} proceeds from step ST1 to step ST3 in FIG. 3 to perform the lowering control in step ST5 and step ST6.
When it is less than Kg / cm ^{2, the process} proceeds from step ST1 in FIG. 4 to step ST11, and the increase control in step ST14 and step ST15 is performed.

In this embodiment, the outside temperature determining means (74) is not provided.

Therefore, also in this embodiment, the outdoor fan
Since the air volume of (26) is set to a low air volume corresponding to the outdoor heat exchange temperature Tc, it is possible to prevent an increase in the high-pressure refrigerant pressure HP and, at the same time, to prevent the outdoor heat exchanger (23) from freezing. At the same time, the wet operation of the compressor (21) can be prevented. As a result, overload of the compressor (21) can be prevented, and reliability can be improved.

FIG. 5 is a control flow showing an embodiment of the third aspect of the present invention.
As shown by a one-dot chain line, another air flow control means (76) and air flow holding means (77) are provided in place of the pressure determination means (73), the outside air temperature determination means (74), and the air flow control means (75). It is provided.

The air volume control means (76) takes in the pressure signal of the high pressure control pressure switch (HPS2) every sampling time, and when the detected pressure is higher than the set pressure (for example, 24 kg / cm ² ), the outdoor fan (26). If the detected pressure is lower than the set pressure (for example, 24 kg / cm ² ), an increase signal for increasing the air volume of the outdoor fan (26) is output to the air volume adjusting means (72).

When the air volume control means (76) outputs the decrease signal and the increase signal, the air volume control means (76) controls the air volume control until the standby time corresponding to the decrease signal and the increase signal elapses. The output of the means (76) is stopped.

Next, control of the air volume of the outdoor fan (26) during the heating operation cycle will be described with reference to FIG .

First, when the control of the outdoor fan (26) is started, in step ST21, the air volume control means (76) determines whether or not the ON signal of the high pressure control pressure switch (HPS2) has been issued. When the output is made, the determination becomes yes and the process moves to step ST22, where it is determined whether or not the air volume of the outdoor fan (26) is the current low air volume L. If the air volume of the outdoor fan (26) is not L with a low air volume, the process proceeds to step ST23, and it is determined whether or not the air volume of the outdoor fan (26) is currently at a medium air volume H.
If the air volume of the outdoor fan (26) is not H at the medium air volume, it is currently the highest air volume HH, so the flow proceeds to step ST24, where the air volume control means (76) outputs a decrease signal, and the air volume adjustment means (72). ) Sets the air volume of the outdoor fan (26) to H, which is a medium air volume. Thereafter, the process proceeds from step ST24 to step ST25, where the air volume holding means (77) outputs the output of the air volume control
After stopping for a minute, the air flow is held at the medium air flow H and the routine returns.

In step ST23, when the air volume of the outdoor fan (26) is the middle air volume H, the determination is YES and the process proceeds to step ST26, where the air volume control means (76) outputs a decrease signal. And the air volume adjusting means (72) is an outdoor fan (26)
Is set to L, which is a low air flow. Then the above steps
Moving from ST26 to step ST27, the air volume holding means (77) stops the output of the air volume control means (76) for 7 minutes, and reduces the air volume to a low air volume L.
And return.

If it is determined in step ST22 that the air flow rate of the outdoor fan (26) is L, which is a low air flow rate, the determination is YES and the process proceeds to step ST28, where the air flow rate control means (76) outputs a decrease signal. And the air volume adjusting means (72) is an outdoor fan (26)
Is set to OFF in the stopped state. Thereafter, the process proceeds from step ST28 to step ST29, where the air volume holding unit (77)
Stopped the output of the air volume control means (76) for 5 minutes,
(26) is stopped and the routine returns.

That is, every time the air flow rate of the outdoor fan (26) is reduced, the change state is maintained for a predetermined time.

On the other hand, in step ST21, if the high-pressure control pressure switch (HPS2) does not output an ON signal, the air volume control means (76) makes a negative determination and returns to step ST30.
And the air flow of the outdoor fan (26) is OFF
It is determined whether or not. If the air flow of the outdoor fan (26) is not OFF in the stopped state, the process proceeds to step ST31, and it is determined whether or not the air flow of the outdoor fan (26) is currently low L.
If the air volume of the outdoor fan (26) is not L with a low air volume, the process proceeds to step ST32, and it is determined whether or not the air volume of the outdoor fan (26) is currently at a medium air volume H. If the air volume of the outdoor fan (26) is not H, which is the middle air volume, since the air volume is HH, which is currently the maximum air volume, the flow returns.

In step ST32, when the air volume of the outdoor fan (26) is the middle air volume H, the determination is YES and the process proceeds to step ST33, where the air volume control means (76) outputs an increase signal. And the air volume adjusting means (72) is an outdoor fan (26)
Is set to the maximum air flow HH. Thereafter, the process proceeds from step ST33 to step ST34, in which the air volume holding means (77) stops the output of the air volume control means (76) for 10 minutes, holds the air volume at the maximum air volume HH, and returns.

If the air flow rate of the outdoor fan (26) is low L in step ST31, the determination is yes and the process proceeds to step ST35, where the air flow rate control means (76) outputs an increase signal. And the air volume adjusting means (72) is an outdoor fan (26)
Is set to H of the middle air volume. Then the above steps
The process moves from ST35 to step ST36, where the air volume holding means (77) stops the output of the air volume control means (76) for 7 minutes, and returns with the outdoor fan (26) held at the medium air volume H.

If the air flow of the outdoor fan (26) is OFF in the stopped state in step ST30, the determination is yes and the process moves to step ST37, where the air flow control means
(76) outputs an increase signal, and the air volume adjusting means (72) sets the air volume of the outdoor fan (26) to L at a low air volume. Thereafter, the process proceeds from step ST37 to step ST38, where the air volume holding unit (77)
Stopped the output of the air volume control means (76) for 5 minutes,
(26) is held at the low airflow L, and the process returns.

That is, each time the air flow rate of the outdoor fan (26) is increased, the change state is maintained for a predetermined time.

Therefore, according to the present embodiment, the outdoor fan (2
When the air volume changes in 6), the air volume does not change for a predetermined period of time, so that the air volume does not decrease rapidly, so that the low-pressure refrigerant pressure can be prevented from excessively lowering. Furthermore,
Since it is possible to prevent hunting of the change in air volume, it is possible to improve the comfort and improve the compressor (2
The load fluctuation of 1) can be suppressed, and the reliability can be improved.

In the above embodiment, the high-pressure refrigerant pressure HP is detected by the high-pressure control pressure switch (HPS2).
The condensing temperature Te (indoor heat exchange temperature) during the heating operation cycle detected by the indoor heat exchange sensor (The) may be used.

The outdoor heat exchange temperature Tc is determined by an outdoor heat exchange sensor.
The detection may be performed using a pressure sensor instead of (Thc).

The number of air flow stages of the outdoor fan (26) is as follows:
Needless to say, the present invention is not limited to the embodiment.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a refrigerant piping system diagram showing a refrigerant circulation circuit.

FIG. 3 is a control flowchart showing air volume control of an outdoor fan at high pressure.

FIG. 4 is a control flowchart showing air volume control of an outdoor fan at low pressure.

FIG. 5 is a control flowchart showing air volume control of another outdoor fan.

[Explanation of symbols]

 1 Refrigerant circuit 4 Refrigerant controller 21 Compressor 23 Outdoor heat exchanger (heat source side heat exchanger) 25 Electric expansion valve 26 Outdoor fan (heat source side fan) 31 Indoor heat exchanger (use side heat exchanger) 72 Air volume control Means 73 Pressure discriminating means 74 Outside air temperature discriminating means 75,76 Air flow control means 77 Air flow holding means Thc Outdoor heat exchange sensor Tha Outside air temperature sensor HPS2 High pressure control pressure switch

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Sumida 1304 Kanaokacho, Sakai-shi, Osaka Daikin Industries, Ltd. Sakai Works Kanaoka Factory (56) References JP-A-57-92641 (JP, A) Sho 61-38344 (JP, A) Japanese Utility Model 1-70046 (JP, U) Japanese Utility Model 4-18264 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 11 / 02 102 F25B 1/00 381 F25B 1/00 383

Claims (3)

(57) [Claims] 1. A compressor (21), a heat source side heat exchanger (23) having a heat source side fan (26), an expansion mechanism (25), and a use side heat exchanger (31) are connected in order. A refrigerant circulation circuit (1) capable of performing a heating operation, an air volume adjusting means (72) for adjusting the air volume by switching the air volume of the heat source side fan (26) to a plurality of stages, and the heat source side heat exchanger (23). Evaporating temperature detecting means (Thc) for detecting an evaporating pressure equivalent saturation temperature in the refrigerant circuit (1), a high pressure detecting means (HPS2) for detecting a condensing temperature equivalent saturated pressure in the refrigerant circuit (1), and the high pressure detecting means (HPS2). Pressure discriminating means (73) for outputting a high-pressure signal when the detected pressure is equal to or higher than the set pressure, and outputting a low-pressure signal when the detected pressure is lower than the set pressure at predetermined time intervals, and the evaporating temperature detecting means. (Thc) temperature signal, and each time the pressure discriminating means (73) outputs a high pressure signal, it corresponds to the evaporating pressure equivalent saturation temperature. So that the low air volume heat source-side fan (2
The lowering signal for sequentially reducing the air volume of 6) is sent to the air volume adjusting means.
(72), and each time the pressure discriminating means (73) outputs a low-pressure signal, the air volume of the heat source side fan (26) is sequentially increased so that the air volume becomes a high air volume corresponding to the evaporating pressure equivalent saturation temperature. An air conditioner comprising an air volume control means (75) for outputting a signal to the air volume adjustment means (72). 2. A compressor (21), a heat source side heat exchanger (23) having a heat source side fan (26), an expansion mechanism (25), and a use side heat exchanger (31) are connected in order. A refrigerant circulation circuit (1) capable of performing a heating operation, an air volume adjusting means (72) for adjusting the air volume by switching the air volume of the heat source side fan (26) to a plurality of stages, and the heat source side heat exchanger (23). ), High-pressure detection means (HPS2) for detecting the saturation pressure corresponding to the condensation temperature in the refrigerant circuit (1), and outside air temperature for detecting the outside air temperature. Takes in pressure signals from the detection means (Tha) and the high pressure detection means (HPS2), and outputs a high pressure signal when the detected pressure is higher than the set pressure, and outputs a low pressure signal when the detected pressure is lower than the set pressure at predetermined time intervals. Temperature detection means (73) and the temperature signal of the outside air temperature detection means (Tha), and the detected outside air temperature is equal to or higher than the set temperature. Then, when the detected outside air temperature is lower than the set temperature, a low-temperature signal is output at predetermined time intervals, and the temperature signal of the evaporation temperature detection means (Thc) is taken in. Each time the means (73) outputs a high-pressure signal, the heat-source-side fan (26) so as to have a low air flow corresponding to the evaporating pressure-equivalent saturation temperature based on the high-temperature signal and the low-temperature signal of the outside air temperature determination means (74)
Of the air flow rate adjusting means (7
2), and each time the pressure discriminating means (73) outputs a low pressure signal, a high air volume corresponding to the evaporating pressure equivalent saturation temperature based on the high temperature signal and the low temperature signal of the outside air temperature discriminating means (74) is obtained. The air volume control means (7) outputs to the air volume adjustment means (72) an increase signal for sequentially increasing the air volume of the heat source side fan (26).
5) An air conditioner comprising: 3. A compressor (21), a heat source side heat exchanger (23) having a heat source side fan (26), an expansion mechanism (25), and a use side heat exchanger (31) are connected in order. A refrigerant circulation circuit (1) capable of performing a heating operation, an air volume adjusting means (72) for adjusting the air volume by switching the air volume of the heat source side fan (26) to a plurality of stages, and in the refrigerant circulation circuit (1). High pressure detection means (HPS2) for detecting the saturation pressure equivalent to the condensing temperature, and the pressure signal of the high pressure detection means (HPS2) are taken in at each sampling time, and when the detected pressure is higher than the set pressure, the air volume of the heat source side fan (26) Air flow control means (76) for outputting a decrease signal for reducing the air flow of the heat source side fan (26) to the air flow amount adjusting means (72) when the detected pressure is lower than the set pressure. When the control means (76) outputs the decrease signal and the increase signal, the waiting time corresponding to the decrease signal and the increase signal elapses. Until the air conditioning apparatus characterized by and a air volume holding means for stopping the output of the air volume control means (76) (77).