JP3075978B2 - Air conditioner operation control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the operation of a multi-system air conditioner in which a plurality of indoor units are connected to one outdoor unit, and more particularly to a method for controlling a compressor at the start of operation. .

[0002]

2. Description of the Related Art In general, a multi-system air conditioner is known in which a plurality of indoor units are connected to one outdoor unit.

[0003] Among such cooling and heating air conditioners, in a variable capacity type air conditioner, a compressor provided in an outdoor unit is driven by a variable capacity means such as an inverter. The compressor capacity during the heating operation of the outdoor unit is
The operating indoor unit itself transmits a required value within the heating capacity variable range to the outdoor unit, and the outdoor unit calculates from this value to determine the actual compressor capacity.

In a multi-system type air conditioner, the refrigerant is also supplied to the use side heat exchanger of the stopped indoor unit in order to prevent the refrigerant from accumulating in the use side heat exchanger of the stopped indoor unit. Circulation is performed, and the capacity of the compressor that takes this into account in the outdoor unit is calculated.

[0005]

When one of the indoor units arranged in multiple rooms is operated for heating, if the indoor temperature or the outside air temperature is low, it takes time to increase the condensing pressure in normal operation. In some cases, the rise of the heating operation was delayed.

An object of the present invention is to provide an operation control method of an air conditioner that can stably raise a room temperature at the start of a heating operation without being affected by the outside air temperature.

[0007]

In order to solve the above-mentioned problems, the present invention according to claim 1 has at least a variable capacity type compressor, a single heat source side heat exchanger, and a plurality of utilization side heat exchangers. A first control unit that automatically controls the capacity of the compressor in accordance with the load of the use side heat exchanger, and the discharge gas temperature of the compressor. And a second control unit that adjusts the first control unit for a predetermined period of time at the start of operation of the air conditioner, and then enables the second control unit. You.

According to the first aspect of the present invention, at the start of the heating operation, the capacity of the compressor is equal to or higher than the normal compressor capacity at the start of the heating operation, regardless of the compressor capacity determined by the request of the indoor unit. By increasing the condensing pressure, the indoor unit heating capacity can be rapidly increased, the room temperature rising time can be shortened, and the power consumption until reaching a predetermined room temperature can be reduced.

According to a second aspect of the present invention, there is provided an air conditioner having a refrigeration cycle having at least a variable capacity compressor, a single heat source side heat exchanger, and a plurality of use side heat exchangers. A first control unit that automatically controls the capacity of the compressor in accordance with the load of the heat exchanger; and a heat source temperature that determines the capacity of the compressor, the number of use-side heat exchangers that are effectively operating, and the capacity of the compressor. A second control unit that adjusts the temperature based on the discharge gas temperature, and activates the first control unit for a predetermined time at the start of operation of the air conditioner, and then activates the second control unit It is configured as follows.

According to a third aspect of the present invention, in the air conditioner operation control method according to the second aspect, the capacity of the compressor is increased as the outside air temperature is low and the number of connected indoor units is large, and the outside air temperature is increased. If the number of connected indoor units is high and the number of connected indoor units is small, it is configured to be set gradually lower according to the degree.

According to the second and third aspects of the present invention, the capacity of the compressor is adjusted based on the outside air temperature and the number of indoor units connected to the outdoor unit, based on the discharge gas temperature of the compressor. However, if the outside air temperature is low and the number of connected indoor units is large, the compressor capacity is increased.If the outdoor air temperature is high and the number of connected indoor units is small, the compressor capacity is optimized by gradually lowering the capacity. Power consumption can be suppressed. If the frequency is higher than necessary in a state where the number of connected units is small, there is a possibility that the protection circuit operates due to a sudden increase in pressure.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described with reference to the drawings.

(I) Configuration of Air Conditioner FIG. 1 shows an embodiment of an air conditioner to which the present invention is applied.

The outdoor unit 100 has a connecting pipe (liquid pipe) 28.
The indoor unit group 101 is connected via a to c and connection pipes (gas pipes) 29a to 29c. This air conditioner can perform cooling and heating operations, and in FIG.
The flow of the refrigerant during cooling is indicated by a solid line, and the flow of the refrigerant during heating is indicated by a broken line.

During cooling, the refrigerant flows out of the compressor 3, the muffler 4, the four-way valve 5, the outdoor heat exchanger 6, the modulator 7, the modulator 8, the strainer 9, and the electric expansion valve 10 for controlling the refrigerant of the main refrigeration circuit. Shunted into three circuits. Each of the branch circuits is provided with a refrigerant control electric expansion valve 11a to 11c, and the refrigerant is supplied to a strainer 12a.
To 12c, liquid pipe side connection ports 23a to 23c, connection pipe 28
a to 28c, and sent to the indoor heat exchangers 2a to 2c. The refrigerant flowing out of the indoor heat exchangers 2a to 2c is connected to the connection pipe 2
Returning to the gas pipe side connection ports 27a to 27c via 9a to 29c, the muffler 13, the four-way valve 5, the accumulator 14,
The flow returns to the compressor 3 via 15.

On the other hand, during the heating, the refrigerant circulates in a path reverse to that of the above-described cooling, so that an arrow is indicated by a broken line and the details are omitted. In addition, 16 is an electromagnetic on-off valve for defrost,
When frost has started or is likely to form frost on the outdoor heat exchanger 6, a portion of the warm-air gas refrigerant discharged from the compressor 3 is provided to the outdoor heat exchanger 6 to prevent defrosting or frost formation. It is for.

Dividing liquid pipe temperature sensors 18a to 18c are attached to the respective dividing circuits on the liquid pipes 28a to 28c side. Similarly, each of the gas pipe side branch circuits is provided with a branch gas pipe temperature sensor 19a to 19c. A compressor discharge temperature sensor 20 is mounted on the discharge side of the compressor 3. Further, the outdoor heat exchanger 6 is provided with an outdoor heat exchanger temperature sensor 21, and an outdoor air temperature sensor 22 is provided on the windward side of the outdoor heat exchanger 6.
Is attached.

The outdoor unit 100 is a microcomputer 17
The microcomputer 17 includes the above-mentioned temperature sensors 18a to 18c, 19a to 19c, 20,
Upon receiving the temperature detection signals from 21 and 22, the outdoor unit 100 is controlled according to a control program stored in advance. The outdoor unit microcomputer 17 and each of the indoor unit microcomputers 27a to 27e to be described later are connected by a communication line (not shown) to communicate temperature data, compressor frequency data, and the like.

The microcomputer 17 includes a compressor discharge temperature sensor 20 and a split liquid pipe temperature sensor 18.
a to 18c and a refrigerant control electric expansion valve 11 based on temperature detection signals from the branch gas pipe temperature sensors 19a to 19c.
Calculation of the valve opening degree of a to 11c is performed.

The electric expansion valves 11a to 11c for controlling the refrigerant are:
The valve opening is adjusted by an attached stepping motor. The microcomputer 17 outputs a pulse to the step motor of each of the refrigerant control electric expansion valves 11a to 11c based on the calculation result by the microcomputer 17. The control of the refrigerant flow rate in the main circuit and the branch circuit is performed. These electric expansion valves 11a-1 for refrigerant control
1c operates, for example, in 511 steps until the valve is fully opened, and the microcomputer 17 outputs a pulse for normal rotation or a pulse for reverse rotation to control the valve opening with a resolution of one step.

In this embodiment, the indoor unit group 101
Each of the indoor units has indoor heat exchangers 2a to 2c. Although not shown, the air conditioner has a blower fan, and the basic structure of the indoor unit itself may be a general structure.

The indoor heat exchangers 2a to 2c are provided with heat exchanger temperature sensors 24a to 24e and indoor suction air temperature sensors 25a to 25e at their air inlets.

Each indoor unit has a microcomputer 26a.
To 26c are built in each microcomputer 2
6a to 26c execute calculation and control of an air blowing amount and the like based on temperature detection signals from the heat exchanger temperature sensors 24a to 24e and the indoor suction air temperature sensors 25a to 25e,
Also, necessary data is exchanged with the outdoor unit-side microcomputer 17 via a communication line (not shown).

(II) Control Operation FIG. 2 shows a control algorithm of the operation control method according to the present invention. This control is performed by the R in the microcomputer 17.
Control programgram and EE previously stored in OM
It is executed according to the data stored in the PROM.

First, when the heating operation is started (step S0), the outside air temperature is detected by the outside air temperature sensor 22 (step S1), and when the outside air temperature is 15 ° C. or lower (step S0).
2, NO), the inverter output frequency Fi calculated according to the request from the indoor unit rises, and the frequency rises to a predetermined value A [H
z] or less (step S3), the frequency Fs is set to a predetermined value A as an initial frequency at the start of operation (step S4).

Here, the value of the rising frequency A is set for each performance rank of the outdoor unit (that is, for each compressor output), and can be determined as shown in FIG. 3, for example.

After starting operation at the rising frequency A, the compressor discharge temperature Tc is read (step S5).

The outdoor unit 100 using the electric expansion valve 9 in the refrigerant circuit sets the compressor discharge temperature to the target value Ts. During operation, the compressor discharge temperature Tc is set to the target value Ts.
It is known that the opening degree of the electric expansion valve 9 is adjusted so that

The compressor discharge temperature Tc is equal to the target temperature Ts.
Is less than the value obtained by subtracting 10 ° C. from step (Step S6, Y
ES) determines that the high pressure is still low, and operates with the frequency Fs kept at the initial frequency A.

If [Ts-Tc] is equal to or higher than 10 ° C. and lower than 5 ° C. (step S7, YES), it is determined that the high pressure is gradually increasing, and the set frequency is reduced by 1 Hz (step S8). .

However, this control is performed once every 30 seconds (step S14), but if the current compressor discharge temperature Tc is equal to or lower than the previous compressor discharge temperature Tc in step S8, the frequency Fs Do not reduce.

If the compressor temperature Tc approaches the target temperature Ts and the relationship of Tc ≧ Ts−5 holds (step S9, YES), in step S10, if the deviation ΔTc of the compressor discharge temperature Tc exceeds 1 ° C. Reduces the frequency Fs by 1 [Hz] and maintains the current frequency when the deviation ΔTc of the compressor discharge temperature Tc is −1 ° C. or more and 1 ° C. or less, and maintains the deviation ΔTc of the compressor discharge temperature Tc.
If Tc is less than -1 ° C, it is determined that the high pressure may be reduced, and an operation of increasing the frequency Fs by 1 [Hz] is performed. Note that the range of the increase or decrease may be a value other than 1 [Hz].

In step S11, the room temperature rises,
When the high pressure increases and the condensing temperature becomes higher than necessary, the indoor unit transmits a signal of pressure reduction (frequency hertz down) to the outdoor unit 100. When this signal is received (step S12), it is determined that the pressure rise is sufficient, the start-up control ends (step S15), and the process shifts to frequency control based on a request from a normal indoor unit.

When the room temperature has reached the indoor set temperature and the compressor 3 has stopped (step S13), since the room temperature has already risen, the pressure rises smoothly when the compressor is restarted to maintain the room temperature. ,
This control becomes unnecessary.

During the rise control, if the frequency drops in the processing steps S8 and S10 and becomes lower than the frequency Fi calculated in response to a request from the indoor unit (step S13, YES), any further It is determined that the high-pressure rise is unnecessary, and this control ends. With the above operation control, the rise time at room temperature can be shortened.

FIG. 5 shows actually measured data showing the rising state at room temperature, the frequency and the integrated power in the case where there is no rise control (conventional) and in the case where there is rise control (the present invention). According to FIG. 5, it can be seen that the time required to raise the room temperature to a predetermined temperature (for example, 24 ° C.) is reduced by ΔT, and the power required for the time can be saved by ΔW.

(III) Application Example Although FIG. 3 shows an example in which the initial frequency at start-up is fixed for each performance rank of the outdoor unit, it is set by the following equation according to the number of connected indoor units and the outside air temperature. May be.

Fs = C1 × (16−outside air temperature) + C2 ×
The number of indoor units connected Here, each coefficient C1, C
2. Reference values of the outside air temperature and the number of connected indoor units are shown in FIG.

In the heating operation, the higher the outside air temperature, the faster the high pressure increases. If there is a sudden pressure rise, the compressor 3 is stopped by the high pressure protection, and there is a possibility that the room temperature may fluctuate. In addition, if the number of connected indoor units is small, the amount of circulating refrigerant for preventing the accumulation of refrigerant in the stopped indoor units can be reduced, so that unnecessary power consumption can be eliminated.

[0040]

As described above, according to the first aspect of the present invention, a normal compressor is used based on the discharge gas temperature of the compressor at the start of the heating operation, regardless of the compressor capacity determined by the request of the indoor unit. By raising the condensing pressure with a capacity higher than the capacity, the indoor unit heating capacity can be rapidly increased, the room temperature rise time can be shortened, and the power consumption until reaching a predetermined room temperature is reduced. be able to.

According to the second and third aspects of the present invention,
Compressor capacity is increased by lowering the outside air temperature and the number of connected indoor units is increased, and when the outside air temperature is high and the number of connected indoor units is small, the compressor capacity is optimized by gradually lowering it according to the degree, and extra power is consumed. Can be suppressed.
If the frequency is higher than necessary in a state where the number of connected units is small, there is a possibility that the protection circuit operates due to a sudden increase in pressure.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a refrigerant circuit of an air conditioner according to the present invention.

FIG. 2 is a flowchart showing a control algorithm of the air conditioner according to the present invention.

FIG. 3 is an explanatory diagram showing an example of a capacity coefficient of a compressor.

FIG. 4 is an explanatory diagram showing another reference value of a capacity coefficient of a compressor.

FIG. 5 is an explanatory diagram showing control characteristics of the air conditioner according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 outdoor unit, 101 indoor unit group 2 a to 2 c indoor unit heat exchanger 3 compressor 4 muffler 5 four-way valve 6 outdoor heat exchanger 7 modulator 8 strainer 9 electric expansion valve for refrigerant control of main refrigeration circuit 10 strainer 11 a to 11 c branch circuit Electric expansion valve for refrigerant control 12a to 12c Strainer of shunt circuit 13 Muffler 14 Accumulator 15 Accumulator 17 Microcomputer 18a to 18c Separating liquid pipe temperature sensor 19a to 19c Separating gas pipe temperature sensor 20 Compressor discharge temperature sensor 21 Outdoor heat exchanger temperature Sensor 22 Outside air temperature sensor 23a to 23c Liquid pipe side connection port 24a to 24c Heat exchanger temperature sensor 25a to 25e Indoor suction air temperature sensor 26a to 26e Indoor unit microcomputer 27a to 27c Gas pipe side connection port 28a 28c connecting pipe 29a~29c connecting pipe

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Hatofo 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Koichi Matsumoto 2-chome Keihanhondori, Moriguchi-shi, Osaka No. 5, No. 5, Sanyo Electric Co., Ltd. (56) References JP-A-3-117846 (JP, A) JP-A-3-175230 (JP, A) JP-A 8-114359 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F24F 11/02 102 F24B 1/00 341 F24B 13/00 104 F24B 29/00 321

Claims (3)

(57) [Claims] At least a variable capacity compressor,
In an air conditioner having a refrigeration cycle having a single heat source side heat exchanger and a plurality of use side heat exchangers, the air conditioner automatically controlling a capacity of the compressor according to a load of the use side heat exchanger. 1 control unit, and a second control unit that adjusts the capacity of the compressor based on the discharge gas temperature of the compressor. When the air conditioner starts operating, the first control unit is controlled for a predetermined time. An operation control method for an air conditioner, wherein the second control unit is enabled after enabling the operation. 2. A compressor of at least a variable capacity type.
In an air conditioner having a refrigeration cycle having a single heat source side heat exchanger and a plurality of use side heat exchangers, the air conditioner automatically controlling a capacity of the compressor according to a load of the use side heat exchanger. And a second control unit for adjusting the capacity of the compressor based on a heat source temperature, the number of effective use-side heat exchangers, and a discharge gas temperature of the compressor. An operation control method for an air conditioner, wherein the first control unit is enabled for a predetermined time at the start of operation of the air conditioner, and then the second control unit is enabled. 3. The operation control method for an air conditioner according to claim 2, wherein the capacity of the compressor is increased as the outside air temperature is low and the number of connected indoor units is large, and the outside air temperature is high and the number of connected indoor units is small. In such a case, the operation control method of the air conditioner is characterized in that the air temperature is set slightly lower according to the degree.