JPH02290456A - Operation controller of air conditioning apparatus - Google Patents

Abstract

PURPOSE:To contrive enlargement of a capacity regulation possibility range correspondent with the decrease of a load by allowing the operation controller to perform drooping control reducing an invertor frequency when the load of a room heat exchanger is reduced to be at equal to or less than a set value while permitting the operation controller to perform a gas bypass and further allowing the operation controller to reduce an air flow of an outdoor fan when the load thereof is equal to or less than a set value. CONSTITUTION:When the loads of room indoor heat exchangers 7a-7c are equal to or less than a set value during operation of a device with the use of an operation control means 51, the output frequency of an invertor 18 is allowed to perform drooping control down to lower limit capable of control with the use of a frequency decrease means 52 and a closing means 17 of a bypass passage 9a is allowed to open with the use of a circulation flow reduce means 54 to make it a gas bypass to reduce the refrigerant circulation flow of a refrigerant circuit 12 so as to perform capacity regulation when the load thereof is not increase more than the set value. When the load thereof is equal to or less than the set value, the air flow of an outdoor fan 3a is changed to the side of a flow air low with the use of an air flow reduce means 53 to correspond to the load so as to make possible the single operation of the indoor heat exchangers.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an operation control device for an air conditioner equipped with a plurality of indoor units. Concerning the improvements made to the previous version.

(Prior Art) Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 58-18581, a compressor whose operating frequency is variably driven by an inverter, an outdoor heat exchanger, a pressure reduction mechanism, and an indoor heat exchanger are sequentially connected. In an air conditioner equipped with a refrigerant circuit and a bypass path that bypasses discharged gas from the main refrigerant circuit to the suction pipe, when the indoor temperature approaches the set temperature, so-called droop control is performed to reduce the output frequency of the inverter, and the bypass By opening the duct and bypassing a portion of the discharged gas to the suction side to reduce the amount of refrigerant circulating in the refrigerant circuit, we are attempting to respond to the decrease in required capacity, in other words, to expand the adjustable range of air conditioning capacity. This is a known technique.

(Problems to be Solved by the Invention) By using the above-mentioned conventional device, even in a so-called multi-type air conditioner in which multiple indoor units are connected in parallel to one outdoor unit, the load on the indoor side can be reduced. When the air conditioning capacity decreases, it is possible to expand the adjustment range of the air conditioning capacity.

However, in the case of a multi-type air conditioner, only the connected indoor unit with a particularly small capacity is in the thermo-on state, and when the temperature is close to the set temperature, the required capacity is compared to the rated air conditioning capacity of the outdoor side. may be extremely small. In such a case, the capacity cannot be sufficiently reduced only by controlling the droop of the compressor and bypassing the discharged gas. If the outdoor capacity is excessive relative to the load, there is a risk that the indoor heat exchanger will freeze during cooling operation, and that the high pressure, discharge pipe temperature, and indoor heat exchanger temperature may rise excessively during heating operation. Therefore, in order to avoid such a situation, the compressor will be stopped due to thermo-off, abnormal stop, etc.

In other words, there is a problem in that the capacity cannot be adjusted in response to minute capacity demands on the indoor side.

The present invention has been made in view of the above, and its purpose is to further reduce the capacity of the compressor when it enters the droop control range, thereby allowing a small-capacity indoor unit to operate independently. The purpose is to expand the range of ability adjustment.

(Means for Solving the Problem) As shown in FIG. 1, the first means for achieving the above object is to use a compressor (1) whose operating frequency is variably driven by an inverter (18) and an air volume. Variable outdoor fan (3
A) A plurality of indoor units (A) to (C) each having an indoor heat exchanger (7) are connected in parallel to an outdoor unit (X) having an outdoor heat exchanger (3) attached thereto. a refrigerant circuit (12), a bypass path (9a) connecting the discharge pipe and suction pipe of the compressor (1) via a pressure reduction mechanism (16) so that discharged gas can be bypassed;
) and opening/closing means (17) for opening and closing the air conditioner.

As an operation control device of the air conditioner, the air volume of the outdoor fan (3a) is set to the standard setting air volume, and the opening/closing means (17) of the bypass path (9a) is closed, and each of the indoor heat exchangers An operation control means (51) is provided to control the output frequency of the inverter (18) according to the loads (7a) to (7C).

Furthermore, load detection means detects the load state of the indoor heat exchangers (7a) to (7c), and the load of the indoor heat exchangers (7a) to (7c) is set to a set value by receiving the output of the load detection means. A frequency reduction means (52) for forcibly stopping the control by the operation control means (51) and reducing the output frequency of the inverter (18) to a controllable lower limit value in the following cases; When the load on the indoor heat exchangers (7a) to (7c) is below the set value even after the control by the frequency reduction means (52), the opening/closing means (17) of the bypass passage (9a) is opened to remove a part of the discharged gas. The circulation amount reducing means (53A) bypasses the heat to the suction side, and the indoor heat exchangers (7a) to (
When the load of step 7c) is below a set value, the air volume reducing means (54A) is provided to switch the air volume of the outdoor fan (3a) from the standard set air volume to a low air volume.

As shown in FIG. 1, the second solution is based on the same air conditioner as the first solution, and uses the same operation control device as the first solution as an operation control device for the air conditioner. means (51), load detection means and frequency reduction means (5
2), and furthermore, when the load on the indoor heat exchangers (7a) to (7C) is below the set value even after the control by the frequency reduction means (52), the air volume of the outdoor fan (3a) is set to the standard setting. Air volume reduction means (5) for switching from air volume to low air volume
4B) and when the air volume of the outdoor fan (3a) is reduced by the air volume reducing means (54B) and the load is below the set value, the opening/closing means (17) of the bypass passage (9a) is opened to reduce the discharge gas. A circulating amount reducing means (5 3 B) is provided for bypassing a portion of the air to the suction side.

As shown in FIG. 2, the third solution is based on the same air conditioner as the first solution, and uses the same operation control device as the first solution as an operation control device for the air conditioner. means (51), load detection means and frequency reduction means (5
2), and further, based on the configuration of the outdoor unit (X) and each of the indoor units (A) to (C) in advance, the capacity reduction by the opening operation of the opening/closing means (17) of the bypass path (9a) and the above-mentioned a setting means (29) for calculating the amount of capacity reduction caused by switching the air volume of the outdoor fan (3a) from the standard setting air volume to a low air volume and setting the magnitude relationship of the amount of capacity reduction; and the frequency reduction means. When the load on the indoor heat exchangers (7a) to (7C) is below the set value even after the control by (52), the means for opening and closing the bypass path (9a) is determined based on the magnitude relationship set by the setting means (29). (17) A first capacity reduction means for reducing the capacity of the opening operation or switching the air volume of the outdoor fan (3a), whichever has a smaller capacity reduction amount;
When the load is still below the set value even after the capacity reduction by the first capacity reduction means, the opening/closing means (17) of the bypass path (9a) is operated based on the magnitude relationship set by the above-mentioned setting means (two).
A second capacity reduction means is provided for reducing the capacity of the outdoor fan (3a) whichever has a larger capacity reduction amount among the opening operation of the outdoor fan (3a) and the air volume switching of the outdoor fan (3a).

A fourth solution is a circulation amount reducing means (53A) which operates the first capacity reducing means to open the opening/closing means (17) of the bypass passage (9a) in the third solving means above.
The second capacity reducing means is an air volume reducing means (
54A).

A fifth solution is that in the third solution, the first capacity reduction means (5) switches the air volume of the outdoor fan (3a) from a standard setting air volume to a low air volume during heating operation.
4B), and the second capacity reducing means is configured by a bypass path (9a
) for opening and closing the opening/closing means (17) of the circulation amount reducing means (
53B).

A sixth solution is that in the third solution, the refrigerant circuit (12) is configured to be able to switch between cooling and heating cycles, and during cooling operation, the first capacity reducing means is connected to the bypass path (9a).
) for opening and closing the opening/closing means (17) of the circulation amount reducing means (
53A), the second capacity reducing means is configured with an air volume reducing means (54A) that switches the air volume of the outdoor fan (3a) from the standard setting air volume to a low air volume, while during heating operation, the first capacity reducing means is the outdoor fan. (3a
) is an air volume reduction means (54B) that switches the air volume of the air flow from the standard setting air volume to a low air volume, and the second capacity reduction means is a bypass passage (9
Each of the opening/closing means (17) in a) is configured with a circulation amount reducing means (5 3 B) for opening the opening/closing means (17).

The seventh solution is the first, second, third, fourth, and fifth solution.
Alternatively, the load detection means in the sixth solution means is configured with indoor heat exchange sensors (Th8a) to (Th8c) that detect the temperature of each of the indoor heat exchangers (7a) to (7c).

In an eighth solution, the load detection means in the first, second, third, or fifth solution is configured with a pressure sensor (PL) that detects discharge pressure.

A ninth solution is such that the load detection means in the first, second, third, or fifth solution is configured with a discharge pipe sensor (Th1) that detects the discharge pipe temperature.

(Function) With the above configuration, in the invention of claim (1), the load of each indoor heat exchanger (7a) to (7c) detected by the load detection means during the operation of the device by the operation control means (52) is When is below the set value, the frequency reduction means (52) performs droop control to reduce the output frequency of the inverter (18) to a controllable lower limit value. When the load does not rise higher than the set value even after the droop control, the circulating amount reducing means (53A) opens the opening/closing means (17) of the bypass passage (9a) to perform hot gas bypass, and the refrigerant Since the amount of refrigerant circulating in the circuit (12) is reduced,
Capacity adjustment is made to accommodate smaller loads on the indoor side. Furthermore, when the load is still below the set value even after the capacity reduction by the circulation volume reduction means (53A), the air volume reduction means (53A)
4A) switches the air volume of the outdoor fan (3a) to a lower air volume side, so the amount of heat exchanged between the refrigerant and the outdoor air in the outdoor heat exchanger (3) decreases, and the capacity can be adjusted in response to the decrease in load. carried out, and an indoor heat exchanger of minimum capacity (e.g. 7
a) One unit can be operated independently.

Therefore, the capacity adjustment corresponding to the reduction in the load on the indoor side is performed while avoiding the operation stoppage of the compressor (1) due to thermo-off etc. as much as possible, and the range in which the capacity can be adjusted is expanded.

In the invention of claim (2), the indoor heat exchangers (7a) to (7
When the load in c) is below the set value, droop control is performed by the frequency reduction means (52) in the same way as in the invention of claim {1}, and when the load is still below the set value, the air volume reduction means ( 54B), circulation amount reducing means (5 3
B), capacity reduction control is performed in order. Therefore, the same effect as the invention of claim (1) above can be obtained.

In the invention of claim (3), when the load on the indoor heat exchangers (7a) to (7C) becomes equal to or less than a set value while the device is being operated by the operation control means (51), the frequency reduction means (52) reduces the capacity. is carried out, and when the load is still below the set value, the first capacity reduction means opens and closes the bypass passage (9a) based on the magnitude relationship of the capacity reduction amount set in advance in the setting means (29). 17) opening operation or outdoor fan (
Among the air volume reductions in 3a), the smaller capacity reduction is performed, and if the load is still below the set value, the second capacity reduction means performs the larger capacity reduction. .

In that case, the capacity is reduced in order from the smallest amount of capacity reduction, so even if the state of change is repeated, such as sagging area, return area, sagging area, etc., the period of change becomes gradual, and hunting is prevented. It will be suppressed as much as possible.

In the invention of claim (4), in the invention of claim (3), the circulation amount reducing means (53A)
Since the air volume reducing means (54A) functions as a second capacity reducing means, the smaller variation due to capacity reduction is preferentially executed, and the invention according to claim (3) above is performed during cooling operation. The effect of this will be obtained.

In the invention of claim (5), in the invention of claim (3), during heating operation, the air volume reducing means (54B) functions as a first capacity reducing means, and the circulation rate reducing means (53B) functions as a second capacity reducing means. Since it functions as a reducing means, it is preferentially executed in the order of the smaller range of change due to capacity reduction during heating operation, and the effect of the invention of claim (3) can be obtained during heating operation.

According to the invention of claim (6), in the invention of claim (3), even when the main refrigerant circuit (12) is configured to be able to switch between cooling and heating cycles, the cooling and heating cycles can be switched between the cooling operation and the heating operation. The capacity reduction is performed preferentially in the order of the smaller amount of capacity reduction, and the effect of the invention of claim (3) can be obtained while performing cooling operation and heating operation according to the indoor demand. Become.

In the invention of claim (7), the above claims (11, (2)
, (31, (4), (51 or (6)), the indoor heat exchanger sensors (Th8a) to (Th8c) function as load detection means, and the indoor heat exchanger temperature drops according to the detected value of the indoor heat exchanger temperature. control and capacity reduction control are performed, and during cooling operation, the indoor heat exchanger (7
During the heating operation due to freezing in a) to (7c), the capacity is adjusted in response to the reduction in the load on the indoor side while avoiding as much as possible the thermo-off stop due to an excessive rise in the indoor heat exchanger temperature.

In the invention of claim (8), the above claim f1). (2)
, (In the invention of 31 or (5), during heating operation, the pressure sensor (P1) functions as a load detection means, and the capacity is increased in response to a decrease in load while avoiding abnormal stoppage due to excessive rise in high pressure as much as possible. Even under heating overload conditions, one minimum capacity indoor heat exchanger (for example, 7a) can be operated independently.

In the invention of claim (9), the above claim +1), (2)
．． In the invention of +31 or (5), during heating operation, the discharge pipe sensor (Th1) functions as a load detection means, and while avoiding abnormal stoppage due to excessive rise in discharge pipe temperature as much as possible,
The capacity is adjusted in response to a decrease in load, and even under heating overload conditions, single indoor heat exchanger (for example, 7a) with the minimum capacity can be operated independently.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 3 onwards.

Figures 3 to 10 are claims (1), (2), and (3).
, Ml, f5), (6) or (7), and FIG. 3 is a refrigerant piping system diagram of an air conditioner. Here, the air conditioner has a multi-type configuration in which three indoor units (A) to (C) are connected in parallel to one outdoor unit (X).

In the outdoor unit (X), (1) is a compressor whose operating frequency is variably driven by an inverter (18);
(2) is a four-way switching valve that switches between forward and reverse directions of refrigerant circulation by switching as shown by the solid line in the figure during cooling operation and as shown by the broken line in the figure during heating operation, and (3) is an outdoor fan (3a) with variable air volume. (4) An outdoor heat exchanger equipped with an outdoor heat exchanger that functions as a condenser during cooling operation and as an evaporator during heating operation.
(4a) is a check valve connected in parallel to the outdoor electric expansion valve (4); (5) is a liquid refrigerant. The receiver (8) is an accumulator for removing the liquid refrigerant in the suction refrigerant, and each of the above-mentioned devices is connected to the main refrigerant pipe (9) so that the refrigerant can flow therethrough.

Each indoor unit (A) also has one indoor heat exchanger (7a) each equipped with an indoor fan (13a).
are arranged, and each of the indoor heat exchangers (7a) to (7c
) are liquid branch pipes (10a) to (1) of the main refrigerant pipe (9).
0c) and gas branch pipes (1 1a) to (1 1c)
are connected in parallel to each other.

In the outdoor unit (X), the refrigerant is depressurized in each of the liquid branch pipes (10a) to (10c) during cooling operation, and the indoor heat exchangers (7a) to (7C) are connected to each of the indoor heat exchangers (7a) to (7C) during heating operation. Indoor electric expansion valves (6a) to (6C) are interposed to adjust the flow rate of refrigerant to the refrigerant.

As mentioned above, the main refrigerant pipe (9) and the liquid branch pipe (10a)
~(10c) and gas branch pipe (1 1a) ~(1 1
e), each device (1) to (8) is connected so that refrigerant can flow, and the heat obtained by heat exchange with outdoor air in the outdoor unit (X) is transferred to each indoor unit (A) to (C). A main refrigerant circuit (12) is configured to discharge into the indoor air.

Moreover, (9a) is a bypass passage for pressure equalization that connects the discharge pipe and suction pipe of the compressor (1) so that the refrigerant can be bypassed, and the bypass passage (9a) includes a cavity as a pressure reducing mechanism. (16) and an electromagnetic on-off valve (17) serving as an on-off means for opening and closing the bypass path (9a) are respectively provided in series. That is, all indoor units (A) to (
When the compressor (1) is stopped due to thermo-off in C), the electromagnetic on-off valve (17) is opened to make the high pressure and low pressure almost equal, thereby preventing restart failure of the compressor (1). During droop control, which will be described later, by opening the bypass passage (9a), a portion of the refrigerant in the main refrigerant circuit (12) is bypassed to the suction side, thereby reducing the capacity. In addition, (14) and (14) are the main refrigerant pipe (9), respectively.
This is a manual shutoff valve installed at the end of the liquid and gas pipes.

Furthermore, the device is equipped with many sensors (
T h1) is a discharge pipe sensor arranged in the discharge pipe to detect the discharge pipe temperature, (T h2) is a suction pipe sensor arranged in the suction pipe to detect the suction pipe temperature, (
T h3) is an outdoor heat exchange sensor that detects the temperature of the outdoor heat exchanger (3), ( T h4) is an outdoor air temperature sensor that detects the outside air temperature from the suction air temperature of the outdoor unit (X), (
Th5a) to (Th5c) are room temperature sensors for detecting the intake air temperature of each indoor unit (A) to (C), respectively, and (Th8a) to (Th8c) are liquid branch pipes (10a) of the outdoor unit (X), respectively. ) to (10c), liquid pipe sensors for detecting the liquid pipe temperature, (Th
7a) to (Th7c) are gas pipe sensors (Th8
a) to (Th8c) are each indoor heat exchanger (7a)
(7c) is an indoor heat exchange sensor as a load detection means for detecting temperature, (P1) is a pressure sensor for detecting discharge pressure, and (HPS) is activated when high pressure Hp reaches a predetermined upper limit value. This is a protective high-pressure switch that abnormally stops the compressor (1).

Next, FIG. 4 shows the internal configuration of the outdoor control device (20) that controls the operation of the outdoor unit h (X) and the outdoor control device (20).
0), (MC) is the motor of the compressor (1), and the motor (MC) includes a relay contact (52C-1), a noise filter (22), and a rectifier circuit. (23), a choke coil (24), and the inverter (18) in order to be connected to an AC three-phase power source (21). Also, (MPI) is an outdoor fan (3a)
The motors (52G), (2OR2), (20R4) and (20R5) are respectively connected to the inverter (18),
It is an electromagnetic relay that operates an electromagnetic on-off valve (17), a four-way switching valve (2), etc., and each of the above-mentioned devices is connected to the single-phase component of the three-phase AC power supply (21), and also connected to the outdoor It is also connected to a control device (20) so that signals can be exchanged. Here, the motor (M
The FI) can be connected to the AC power source in two ways, and the normally closed contact (52FH) of the electromagnetic relay (not shown) built into the outdoor control device (20) is connected to the FI). If it is connected, the standard high air flow rHJ will be used, and if the electromagnetic relay regular contact point (52FL) is connected, it will be the low air flow rHJ.
Each LJ is configured to operate an outdoor fan (3a). Furthermore, (EVo). (EV+)
~ (EV3) is the outdoor electric expansion valve (
This is a stepping motor that drives the opening adjustment mechanism (not shown) of the indoor electric expansion valve (6) and the indoor electric expansion valve (6). Each of the external devices described above is connected to the outdoor control device (20) so as to be able to send and receive signals, and its operating state is controlled by the outdoor control device (20).

Furthermore, (63H2) is a pressure switch for high pressure control during heating operation, and this switch (63H'2) is signal-connected to the outdoor control device (20) through a connection terminal (C N 3).

Further, inside the outdoor control device (20), normally open contacts (RY+) to (RY4) of electromagnetic relays are connected in parallel to the single-phase AC power source. These are, in order, electromagnetic relay (52C), (20R2), (2OR4). and (20R5) in series, and are opened and closed in response to signals from the outdoor control device (20).
This turns each of the electromagnetic relays above on and off.

The outdoor control device (20) includes the outdoor side sensors (Th1) to (Th4), (Thl3a
) ~(Th6c), (Th7a) ~(T
h7c) is connected so that the signal can be inputted, and each indoor sensor (Th5a) to (Th5c),
Signals (Th8a) to (Th8c) can be input.

In the figure, (26) is a sawtooth wave smoothing circuit, (2
7) is a transmission synchronization circuit, (28) is a device protection circuit, (
63H+) is high pressure for equipment protection. Kaswitch, (49
F) is a protective thermostat for the motor (MF1) of the outdoor fan (3a), and (CN51) is an output terminal for outputting a signal to the drive circuit (not shown) of the inverter (18).

Here, the memory circuit (29) built in the outdoor control device (20) stores information about the indoor heat exchangers (7a) to (7c) during the cooling operation of the device, as shown in the table below, an example of which is shown in the table below.
Bypass path (9a) is installed to prevent freezing when the load is small and to reduce the ability to prevent high pressure from rising during heating operation.
Regarding the capacity reduction due to the opening operation of the electromagnetic on-off valve (17), that is, the hot gas bypass and the air volume reduction of the outdoor fan (3a), the amount of capacity reduction due to these controls is calculated, and the magnitude relationship is set in advance.

However, on the left side of the above table, the differential pressure ΔP is determined in advance so that during cooling operation, the capacity/reduction amount due to hot gas bypass is greater than the capacity reduction amount due to fan airflow reduction.
The pressure difference between high and low when the pressure reduction characteristics of the capillary (16) are set, for example, when the high pressure Hp is 11.39 (Kg/l)
In case 2), the low pressure Lp is 343 (κg/m2)
It is made so that. In addition, the temperature difference ΔT is the suction air temperature T when the outdoor fan (3a) has a strong air volume rHJ.
a (here 20.45℃) and outdoor heat exchanger (3)
This is the temperature difference between the refrigerant temperature T3 (30.8° C. in this case). Also, the numbers in the table during heating operation are as follows:
The difference in pressure ΔP and the difference in temperature ΔT are shown when the values are set to the above values during cooling operation, respectively.

In the case of the table above, during heating operation, the same capillary (16
) configuration, the pressure difference between high and low is larger than during cooling operation, so the amount of capacity reduction due to hot gas bypass is also large, whereas the temperature difference ΔT is conversely smaller, and the capacity reduction due to hot gas bypass during heating operation is The amount of reduction is greater.

From the above, as shown on the right side of the above table, the magnitude relationship of the capacity reduction amount is preset in the memory circuit (29), and the memory circuit (29) has a function as a setting means.

Next, FIG. 5 shows the electrical connection with external equipment and the internal configuration of the indoor control device (30) arranged in each of the indoor units (A) to (C). In the figure, (MF) is an indoor fan (1 3
The motor in a) received single-phase AC power and switched to weak wind rLJ and strong wind rHJ in descending order of air volume using each relay terminal (RYa) to (RYc), and a thermo-off signal during heating operation was input. The light breeze is set to ``LL'' only during the ventilation mode such as when the air blower is in use.

The indoor control device (30) also includes a room temperature sensor (
Signals from Th5) and indoor heat exchange sensor (Th8) are input, and it is connected to the outdoor control device (20) and remote control device (RCS) so that signals can be exchanged.

During cooling operation of the device, the four-way selector valve (2) is switched to the side shown by the broken line in Figure 2, and the indoor electric expansion valves (6a) to (6C) are opened while the outdoor electric expansion valve (4) is open. The operation is performed while adjusting the temperature according to the degree of superheating, and the discharged refrigerant is condensed in the outdoor heat exchanger (3), and each indoor electric expansion valve (6a) to (6C
), and circulates to evaporate in each indoor heat exchanger (7a) to (7C), while during heating operation, the four-way selector valve (2) switches to the solid line side in the figure, and each indoor electric expansion valve(
With the opening degrees of 6a) to 6c slightly open, operation is performed while appropriately adjusting the opening degree of the outdoor electric expansion valve (4), and the discharged refrigerant flows through each indoor heat exchanger (7a) to ( 7C), is depressurized by the outdoor electric expansion valve (4), and circulated to be evaporated in the outdoor heat exchanger (3).

Next, regarding the control by the outdoor control device (20),
This will be explained based on the flowcharts of FIGS. 6 and 8.

Fig. 6 shows the control contents during cooling operation, and in step Sl, each indoor heat is While controlling the normal cooling operation that adjusts the output frequency F of the inverter (18) according to the load of the exchangers (7a) to (7c), in step S2, each indoor heat exchange sensor (Th8a) to (Th8c) One of the detected indoor heat exchanger temperatures T8a-T8c is the indoor set temperature T.
It is determined whether or not the temperature is below sl (for example, a value of about 1°C), and when the determination is NO, that is, in the temperature decreasing region (region (a) in Figure 7), the above normal control is performed, but if the determination is YES, the above normal control is performed. It is determined that the compressor (1) has entered a droop region (region (b) in FIG. 7) in which the capacity should be reduced, and the following droop control is performed.

That is, in step S3, the output frequency F of the inverter (18) is forcibly lowered, and in step S4, the output frequency F is lowered for a predetermined period of time (
Wait until a period of time (for example, about 30 seconds) has elapsed, and in step S5 determine whether any of the indoor heat exchanger temperatures T8a-T8c is below the set temperature Tsl, and if it is below, further The output frequency F of the inverter (18) is controllable lower limit value Fsin (for example, 29Hz
The above drooping control is performed until it becomes equal to (value of degree).

Then, in the determination in step S6 above, the inverter (
18) When the output frequency F reaches the lower limit value Fslnl:,
It is determined that there is a limit to capacity reduction with droop control alone, and the capacity reduction control from step 87 onwards is performed.

First, in step S7, the electromagnetic on-off valve (17) of the bypass path (9a) is opened to perform hot gas bypass, based on the magnitude relationship of the capacity reduction amount in the upper row on the right side of the table above.
In steps s8 and s9, after making the same determination as in steps S4 and S5 above, the indoor heat exchanger temperature 78a-T8c is still
If any of them is below the set temperature Tsl, it is determined that it is necessary to further reduce the capacity, and step Sll is performed.
1, the outdoor fan (3a) is set to a low air volume rLJ.

After that, in steps Sll and Sl2, the above step S4 is performed.
, the same determination as in S5 is made, and each indoor heat exchanger temperature T
If any of 8a to T8c is lower than the set temperature Tsl, it is determined that the capacity cannot be adjusted by the capacity reduction control described above, and thermo-on control is performed in step SI3 to stop the compressor (1).

In addition, in the above flow, step SS, S9 or S
12, when any of the indoor heat exchanger temperatures T8a to T8c becomes higher than the set temperature Tsl, it is determined that the temperature is outside the drooping region, and the drooping outside control, that is, the no-change region shown in FIG. Control is performed in the area (C) in the figure) or the return area (area (d) in the figure).

Next, FIG. 8 shows the control contents during heating operation. In this case, the basic control is the same as the control during cooling operation shown in FIG. 6, and each step R1 to R6, R8
, R9 and Rl1-13 are the same as steps S1-s6, sB, s9 and Sll-SI3 in FIG. 5, respectively. However, steps R2, Rs, R9 and Rl
2, it is determined whether each indoor heat exchanger temperature 78a-T8c is higher than the set temperature Tvl (for example, a value of about 53° C.) during heating operation.

Then, in step R7, the air volume of the outdoor fan (3a) is reduced to a low air volume rLJ, and in step RIO, the air volume of the outdoor fan (3a) is reduced to a low air volume rLJ.
The electromagnetic on-off valve (17) in a) is opened. That is, based on the magnitude relationship of the capacity reduction amount in the lower part of the above table, priority is given to air volume reduction over hot gas bypass, contrary to capacity reduction control during cooling operation.

In the above flow, step Sl or R1 sets the air volume of the outdoor fan (3a) to the standard setting air volume (strong air volume "H").
), and with the electromagnetic on-off valve (on-off means) (17) of the bypass path (9a) closed, each indoor heat exchanger (7a) to
An operation control means (51) is configured to control the output frequency F of the inverter (18) according to the load of the indoor heat exchanger (7a) to (7C).
C) Frequency reduction that changes the output frequency of the inverter (18) to be reduced to a controllable lower limit value by forcibly stopping the control by the operation control means (51) when the load of C) is below a set value. Means (52) are configured.

Further, in step S7 of FIG. 6, if the load is still below the set value even after the control by the frequency reduction means (52), the opening/closing means (17) of the bypass path (9a) is opened to remove a part of the discharged gas. A circulation amount reducing means (53A) is configured to bypass the intake side, and in step 810, when the load is still below the set value even after the control by the circulation amount control means (53A), the air volume of the outdoor fan (3a) is set to the standard setting. An air volume reducing means (54) is configured to switch the air volume to the air volume side.

On the other hand, in step R7 of FIG. 8, the frequency control means (
When the load is still below the set value even after the control by step RIG, the air volume control means (54B) is configured to switch the air volume of the outdoor fan (3a) from the set standard air volume to the low air volume side. When the load is below the set value even after the control by 53B), the circulation amount reducing means (53B) opens the electromagnetic on-off valve (17) of the bypass path (9a) and bypasses a part of the discharged gas to the suction side. has been done.

Therefore, in the invention of claim (1), the operation control means (
51), when the load of each indoor heat exchanger (7a) to (7C) detected by the load detection means (Th8a) to (Th8c) becomes less than the set value, the frequency reduction means ( 52), the inverter (18)
Droop control is performed to reduce the output frequency F of .

That is, as shown in FIG. 7, during cooling operation, for example, in the indoor unit (A), the indoor heat exchanger temperature 78a decreases from the temperature drop region (region (a) in the figure) to the set temperature Ts.
When it becomes less than l (drooping region (b) in the figure), the output frequency F of the inverter (18) is lowered to reduce the capacity to cope with the load.

However, if the indoor load does not rise above the set value while the droop control is being performed, and the indoor heat exchanger temperature T8a does not recover to a higher level than TsL, freezing will occur on the surface of the indoor heat exchanger (7a). There is a risk. Here, in the invention of claim {1}, first, the circulation amount reducing means (53A) operates the electromagnetic on-off valve (17) of the bypass path (9a) to open the hot gas bypass in the main refrigerant circuit (12). Since the refrigerant circulation amount is controlled to be reduced, the capacity can be reduced in response to a smaller indoor load. Furthermore, when the indoor heat exchanger temperature 78a still does not rise even with the capacity reduction by the circulation amount reducing means (53A) and is about to approach the thermo-off state (below the lower limit value TslIl) from the drooping region (b), the air amount reducing means (53A) 54A), the outdoor fan (3a)
Since the air volume is switched to the low air volume rLJ, the amount of heat exchange between the refrigerant and the outdoor air in the outdoor heat exchanger (3) decreases, resulting in a no-change region (region (c) in the figure) or a recovery region (region (c) in the figure). The area above the boundary value Ts2 (for example, a value of about 3 degrees Celsius) (
By moving to step d)), it is possible to adjust the capacity in response to a smaller load on the indoor side while avoiding stopping the operation of the compressor (1) due to thermo-off as much as possible.

On the other hand, during heating operation, as shown in FIG. 9, for example, the indoor heat exchanger temperature 78a in the indoor unit (A) rises, and goes from the temperature increase region (region (e) in the figure) to the set temperature TvL or higher. When entering the drooping region (region (e) in the figure), the thermo-off state (upper limit T
However, the frequency reduction means (52
), circulation volume reduction means (53A) and air volume reduction means (54
According to A), droop control and capacity reduction control similar to those described above are performed, and capacity adjustment is performed according to the decrease in load, while avoiding stopping of the compressor (1) due to thermo-off as much as possible.
This results in a transition to a no-change region (region (g) in the diagram) or a recovery region (region (h) below the boundary value Ts2 in the diagram).

As described above, for example, even when the capacity of the indoor heat exchanger (7a) in the indoor unit (A) is small in the configuration as in the above embodiment, it is possible to operate one small-capacity indoor heat exchanger (7a) independently. This makes it possible to expand the range of ability adjustment.

In the invention of claim 2, indoor heat exchangers (7a) to (7c
) is below the set value, the above claim (
Similar to the invention of 1), the frequency reduction means (52) performs droop control, and when the load is still below the set value,
Air volume reduction means (54B), circulation volume reduction means (53B)
), capacity reduction control is performed in order. therefore,
The same effect as the invention of claim (1) above can be obtained.

In the invention of claim (3), when the load on the indoor heat exchangers (7a) to (7C) becomes equal to or less than a set value while the device is being operated by the operation control means (51), the frequency reduction means (52) reduces the capacity. After this has been carried out, if the load is still below the set value, based on the magnitude relationship of the capacity reduction amount set in advance in the setting means (29), the first capacity reduction means (in the above embodiment, during cooling operation, the circulation During heating operation, the air volume reduction means (53A) and the air volume reduction means (54B)) open the electromagnetic on-off valve (17) of the bypass path (9a) or reduce the air volume of the outdoor fan (3a), whichever has the smaller capacity reduction amount. Therefore, the capacity can be adjusted in response to the reduction in load. Furthermore, if the load is still below the set value, the second capacity reduction means (in the above embodiment, the air volume reduction means (54A) during cooling operation and the circulation amount reduction means (53B) during heating operation) reduces the capacity by a large amount. The capacity of the indoor side is reduced, and the capacity is adjusted in response to the reduction in the load on the indoor side.

In this case, since the execution is performed in order of decreasing capacity, hunting can be prevented as much as possible. That is, as shown in FIG. 10, for example, in the indoor unit (A) during heating operation, the indoor heat exchanger temperature T8a changes between a droop region where it is higher than the set temperature Tvl and a return region where it is lower than the boundary value Ts2. When the situation is repeated, there is a possibility that the temperature change in the indoor heat exchanger temperature T8a becomes large and hunting occurs, but in the present invention, since the reduction is performed from the side with the smallest amount of capacity reduction, the cycle becomes gentle. . Therefore, hunting can be suppressed as much as possible while expanding the adjustable range of performance.

In the invention of claim (4), in the invention of claim (3), the circulation amount reducing means (53A)
Since the air volume reducing means (54A) functions as a second capacity reducing means, the smaller range of change due to capacity reduction is preferentially executed, and therefore, the invention of claim (3) Effective results can be obtained.

In the invention of claim (5), in the invention of claim (3) above, during heating operation, the air volume reducing means (54B) is
It functions as a capacity reduction means, and a circulating amount reduction means (5 3
Since B) functions as the second capacity reduction means, it is preferentially executed in the order of smaller variation due to capacity reduction during heating operation, and thus the effect of the invention of claim (3) can be obtained.

In the invention of claim (6), in the invention of claim (3), the main refrigerant circuit (12) is configured to be able to switch between cooling and heating cycles, and the main refrigerant circuit (12) is configured to be able to switch between cooling and heating cycles. ) and claim (5), so the effectiveness of the invention of claim (3) can be obtained while performing cooling operation and heating operation according to indoor demands. become.

In the invention of claim (7), the above claims (1) and (2)
．． (3). In the invention of (4), (5) or (6), the indoor heat exchanger sensors (Th8a) to (Th8c) function as load detection means, and the drooping occurs according to the detected value of the indoor heat exchanger temperature T8a-T8c. control and capacity reduction control are performed.

Therefore, during cooling operation, the indoor heat exchangers (7a) to (7c) freeze due to a decrease in the load on the indoor side, and during heating operation, the indoor heat exchanger (7a) to (7c) freezes due to an excessive rise in the indoor heat exchanger temperature, while avoiding as much as possible the thermo-off stoppage. Capacity can be adjusted in response to load reduction, and therefore each invention can be made more effective.

Next, a second embodiment according to the invention of claim (8) will be described. In this embodiment as well, the configurations of the refrigerant piping system, the outdoor control device (20), and the indoor control device (30) are the same as in the first embodiment. However, in FIG. 3, a pressure sensor (P1) placed in the discharge pipe functions as a load detection means.

FIG. 11 is a flowchart showing the control details, and steps Q1 to Q+3 correspond to steps R1 to RI3 in FIG. 8.

However, in steps Q2, QS, and Q9, when the contact point of the pressure sensor (P1) is turned on, it is determined that the load is less than the set value and the load falls into the drooping region.

Therefore, in the invention of claim (8), the above claim +1
1, (2). In the invention of (3) or (5), as shown in FIG. 12, during heating operation, the set pressure Psi (for example, (24 Kg/i
2) or more and the drooping area (area (j) in the figure)
When the high pressure switch (HPS) is activated, the upper limit pressure Ps2 (for example, a value of about 27.5Kg/m2) is reached.
There is a risk that the high pressure Hp will rise until it reaches Hp, but the above-mentioned droop control and capacity reduction control will adjust the capacity in response to the decrease in load, while avoiding further shutdown of the equipment due to an excessive rise in high pressure as much as possible. No change area (area (k) in the figure) and return area (boundary value Ps2 in the figure (for example, 19.2Kg/
A transition to the area (g) below (a value of about a2) is performed,
Minimum capacity indoor heat exchanger (
For example, 7a) Single operation of one unit becomes possible.

Although examples are omitted, in the invention of claim (9),
In the flow chart of FIG. 11 and the characteristic diagram of FIG. For example, a value of about 135°C) and a boundary value (for example, a value of about 120°C) are used to reduce the load while avoiding abnormal stoppage of the compressor (1) due to excessive rise in discharge pipe temperature as much as possible. Capacity can be adjusted accordingly, and even under heating overload conditions, one minimum capacity indoor heat exchanger (for example, 7a) can be operated independently.

(Effect of the invention) As explained above, according to the invention of claim (1), in an air conditioner in which a plurality of indoor units are arranged, the load on the indoor heat exchanger is reduced to be below the set value. At times, droop control is performed to reduce the inverter frequency, and when the load is below the set value, hot gas bypass is performed, and when the load is below the set value, the outdoor fan air volume is reduced. It is possible to adjust the capacity in response to a decrease in load while avoiding the stoppage of the compressor due to thermo-off, etc. as much as possible, and thus it is possible to expand the range in which the capacity can be adjusted.

According to the invention of claim (a), when the load is reduced, droop control is performed, and when the load is less than the set value due to the droop control, the outdoor fan air volume is reduced, and then when the load is less than the set value, the outdoor fan air volume is reduced. Since the gas bypass is performed, the same effect as the invention of claim (1) above can be obtained.

According to the invention of claim (3), the magnitude relationship of the capacity reduction is set in advance, and droop control is performed when the load is reduced, and when the load is less than the set value due to the droop control,
Between hot gas bypass and outdoor fan air volume reduction, we prioritized the capacity reduction based on the smaller amount of capacity reduction, so while adjusting the capacity in response to the decrease in load, we slowed down the load change cycle. Hunting can be suppressed.

According to the invention of claim (4), in the invention of claim (3), during cooling operation, priority is given to the hot gas bypass, which has a small amount of capacity reduction, to reduce the capacity.
The invention of claim (3) can be made more effective.

According to the invention of claim (5), in the invention of claim (3), during heating operation, the capacity reduction is performed with priority given to outdoor fan air volume reduction, which has a small capacity reduction amount.
The invention of claim (3) can be made more effective.

According to the invention of claim (6), in the invention of claim (3), the hot gas bypass is prioritized during cooling operation, and the outdoor fan air volume reduction is prioritized during heating operation to reduce the capacity. In both the cooling operation and the heating operation, the capacity can be reduced in the order of the smaller amount of capacity reduction, and therefore the invention of claim (3) can be made more effective.

According to the invention of claim (7), the above claim (1). (
2). (3). (41, Since the load detection means in the invention of (51 or (6)) is constituted by an indoor heat exchanger sensor that detects the indoor heat exchanger temperature, the indoor heat exchanger is frozen during cooling operation, and the indoor heat exchanger is not exchanged during heating operation. While avoiding as much as possible the compressor's thermo-off stop due to excessive rise in chamber temperature,
Capacity can be adjusted in response to a decrease in load.

According to the invention of claim (8), the above-mentioned claim (1), (
Since the load detection means in the invention of 2), (3) or (5) is constituted by a pressure sensor that detects the discharge pressure, abnormal stoppage of the compressor due to excessive rise in high pressure can be avoided as much as possible during heating operation. The capacity can be adjusted in response to a decrease in load, and even under heating overload conditions, a single indoor heat exchanger with the minimum capacity can be operated independently.

According to the invention of claim (9), the above claim [1]. (
Since the load detection means in the invention of 2), (3) or (5) is constituted by a discharge pipe sensor that detects the discharge pipe temperature,
During heating operation, capacity can be adjusted in response to load reduction while avoiding abnormal compressor stoppage due to excessive rise in high pressure. Even under heating overload conditions, the minimum capacity indoor heat exchanger The machine can be operated independently.

[Brief explanation of drawings]

FIGS. 1 and 2 are block diagrams showing the configuration of the present invention. Fig. 3 to Fig. 10 show the first embodiment, Fig. 3 is a refrigerant piping system diagram of the air conditioner, Fig. 4 is an electric circuit diagram of the outdoor control device, and Fig. 5 is an electric circuit of the indoor control device. Figure, 6th
Figure 7 is a flowchart showing the control details during cooling operation, Figure 7 is a characteristic diagram showing the relationship between changes in indoor heat exchanger temperature and control mode settings during cooling operation, and Figure 8 is a diagram showing the relationship between control mode settings during heating operation. Flowchart diagram showing control contents, No. 9
The figure is a characteristic diagram showing the relationship between the indoor heat exchanger temperature and the control mode setting during heating operation, Figure 10 is an explanatory diagram showing the repetition state between the droop region and the return region of the control mode, and Figure 11
11 and 12 show the second embodiment, FIG. 11 is a flowchart showing control details, and FIG. 12 is a characteristic diagram showing the relationship between changes in high pressure and control mode. 1 Compressor 3 Outdoor heat exchanger 3a Outdoor fan 7 Indoor heat exchanger 9a Bypass path 12 Main refrigerant circuit 16 Pressure reduction mechanism 17 Electromagnetic on-off valve (opening/closing means) 18 Inverter 29 Setting means Thl Th8 P1 X Operation control means Frequency reduction means circulation Volume reducing means Air volume reducing means Discharge pipe sensor (load detection means) Indoor heat exchange sensor (load detection means) Pressure sensor (load detection means) Outdoor unit Indoor unit A-C Patent applicant Daikin Industries, Ltd. Agent: Hiroshi Maeda, patent attorney (and 2 others) "f-= Compressor outdoor heat exchanger outdoor unit Fig. 10 Fig. 12 Fig. 4 Fig. 9 Fig.

Claims (9)

[Claims] (1) Compressor (1) whose operating frequency is variably driven by an inverter (18) and outdoor fan (3a) with variable air volume
A refrigerant formed by connecting a plurality of indoor units (A) to (C) having an indoor heat exchanger (7) in parallel to an outdoor unit (X) having an outdoor heat exchanger (3) attached thereto. a circuit (12), a bypass path (9a) connecting the discharge pipe and suction pipe of the compressor (1) via a pressure reduction mechanism (16) so that discharged gas can be bypassed; In an air conditioner equipped with an opening/closing means (17) for opening and closing, when the air volume of the outdoor fan (3a) is set to the standard air volume and the opening/closing means (17) of the bypass path (9a) is closed, The indoor heat exchangers (7a) to (7c) include an operation control means (51) that controls the output frequency of the inverter (18) according to the load of each of the indoor heat exchangers (7a) to (7c); and a load detection means for detecting the load state of the indoor heat exchangers (7a) to (7c), receiving the output of the load detection means, and controlling the operation control means (51) when the load of the indoor heat exchangers (7a) to (7c) is below a set value. A frequency reduction means (52) for forcibly stopping and changing the output frequency of the inverter (18) to reduce it to a controllable lower limit value; When the loads of (7a) to (7c) are below the set value, the opening/closing means (1) of the bypass path (9a)
7) is opened to bypass a part of the discharged gas to the suction side, and the circulation amount reducing means (53A)
If the load on the indoor heat exchangers (7a) to (7c) is below the set value even after the control by A), the outdoor fan (3a)
1. An operation control device for an air conditioner, comprising an air volume reducing means (54A) for switching the air volume from a standard setting air volume to a low air volume. (2) A compressor (1) whose operating frequency is variably driven by an inverter (18) and an outdoor fan (3a) whose air volume is variable
A refrigerant formed by connecting a plurality of indoor units (A) to (C) having an indoor heat exchanger (7) in parallel to an outdoor unit (X) having an outdoor heat exchanger (3) attached thereto. a circuit (12), a bypass path (9a) connecting the discharge pipe and suction pipe of the compressor (1) via a pressure reduction mechanism (16) so that discharged gas can be bypassed; In an air conditioner equipped with an opening/closing means (17) for opening and closing, when the air volume of the outdoor fan (3a) is set to the standard air volume and the opening/closing means (17) of the bypass path (9a) is closed, The indoor heat exchangers (7a) to (7c) include an operation control means (51) that controls the output frequency of the inverter (18) according to the load of each of the indoor heat exchangers (7a) to (7c); a load detection means for detecting the load state of the inverter (18); and a load detection means for receiving the output of the load detection means, and controlling the output frequency of the inverter (18) when the load of the indoor heat exchangers (7a) to (7c) is below a set value. Frequency reduction means (
52), and when the load on the indoor heat exchangers (7a) to (7c) is below the set value even after the control by the frequency reduction means (52), the air volume of the outdoor fan (3a) is changed from the standard set air volume to a low air volume. and when the air volume reducing means (54B) is reducing the air volume of the outdoor fan (3a) and the load is below a set value, the bypass path (9a) opening/closing means (17). circulation amount reducing means (53) that opens to bypass a part of the discharged gas to the suction side;
B) An operation control device for an air conditioner, characterized by comprising: (3) A compressor (1) whose operating frequency is variably driven by an inverter (18) and an outdoor fan (3a) whose air volume is variable
A refrigerant formed by connecting a plurality of indoor units (A) to (C) having an indoor heat exchanger (7) in parallel to an outdoor unit (X) having an outdoor heat exchanger (3) attached thereto. a circuit (12), a bypass path (9a) connecting the discharge pipe and suction pipe of the compressor (1) via a pressure reduction mechanism (16) so that discharged gas can be bypassed; In an air conditioner equipped with an opening/closing means (17) for opening and closing, when the air volume of the outdoor fan (3a) is set to the standard air volume and the opening/closing means (17) of the bypass path (9a) is closed, It includes an operation control means (51) that controls the output frequency of the inverter (18) according to the load of each of the indoor heat exchangers (7a) to (7c), and also includes an operation control means (51) that controls the output frequency of the inverter (18) in accordance with the load of each of the indoor heat exchangers (7a) to (7c). A)～
Based on the configuration of (C), the capacity is reduced by opening the opening/closing means (17) of the bypass path (9a) and the capacity is reduced by switching the air volume of the outdoor fan (3a) from the standard setting air volume to a low air volume. a setting means (29) for calculating the capacity reduction amount and setting the magnitude relationship of the capacity reduction amount; a load detection means for detecting the load state of each of the indoor heat exchangers (7a) to (7c); Frequency reduction that changes the output frequency of the inverter (18) to be reduced to a controllable lower limit value when the load on the indoor heat exchangers (7a) to (7c) falls below a set value in response to the output of the means. Means (52
), and when the load of the indoor heat exchangers (7a) to (7c) is below the set value even after the control by the frequency reduction means (52), the bypass is performed based on the magnitude relationship set by the setting means (29). A first capacity reduction means for reducing the capacity of the opening operation of the opening/closing means (17) of the passageway (9a) or switching the air volume of the outdoor fan (3a), whichever has a smaller capacity reduction amount, and a capacity reduction by the first capacity reduction means. If the load is still below the set value, the opening operation of the opening/closing means (17) of the bypass path (9a) or the air volume switching of the outdoor fan (3a) is performed based on the magnitude relationship set by the setting means (29). 1. An operation control device for an air conditioner, comprising: second capacity reduction means for reducing capacity by a larger amount of reduction. (4) During cooling operation, the first capacity reducing means is the bypass path (9
The circulation amount reducing means (53A) opens the opening/closing means (17) of a), and the second capacity reducing means operates the outdoor fan (3).
Claim (3) characterized in that it is an air volume reduction means (54A) for switching the air volume in a) from a standard setting air volume to a low air volume.
An operation control device for the air conditioner described above. (5) During heating operation, the first capacity reduction means is an outdoor fan (3
The air volume reduction means (54B) switches the air volume in a) from the standard setting air volume to a low air volume, and the second capacity reduction means is a circulation volume reduction means (53B) that opens the opening/closing means (17) of the bypass passage (9a). Claim (3) characterized in that
An operation control device for the air conditioner described above. (6) The refrigerant circuit (12) is configured to be able to switch between cooling and heating cycles, and during cooling operation, the first capacity reducing means is connected to the bypass path (9a
) for opening and closing the opening/closing means (17) of the circulation amount reducing means (
53A), and the second capacity reducing means is an outdoor fan (3a
) is an air volume reduction means (54A) that switches the air volume of the outdoor fan (3a) from the standard setting air volume to a low air volume.
) is an air volume reduction means (54B) for switching the air volume from a standard setting air volume to a low air volume, and the second capacity reduction means is a circulation volume reduction means (53B) for opening the opening/closing means (17) of the bypass passage (9a). The operation control device for an air conditioner according to claim 3, characterized in that: (7) The load detection means is for each indoor heat exchanger (7a) to (7c).
) Indoor heat exchanger sensors (Th8a) to (T
Claims (1) and (2) characterized in that h8c)
, (3), (4), (5) or (6). (8) Claims (1) and (2) characterized in that the load detection means is a pressure sensor (P1) that detects discharge pressure.
, (3) or (5). (9) Claim (1), wherein the load detection means is a discharge pipe sensor (Th1) that detects the discharge pipe temperature;
The operation control device for an air conditioner according to (2), (3) or (5).