JP2730398B2 - Multi-room air conditioning system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room air conditioning system in which a plurality of indoor units are connected to one outdoor unit, and the flow rate of refrigerant is controlled by an electric expansion valve.

[0002]

2. Description of the Related Art In recent years, a multi-room air conditioner system in which a plurality of indoor units are connected to one outdoor unit has been increasingly accepted by consumers of ordinary households in terms of space saving and aesthetic appearance. is there.

Conventionally, in this multi-chamber air conditioning system, a refrigerant circulating amount control device that uses a variable capacity (frequency) compressor to control the amount of refrigerant circulating to each indoor unit in a liquid side refrigerant pipe of a refrigeration cycle. And a compressor that controls the compressor capacity and the amount of refrigerant circulating to each indoor unit based on the ratio of the capacity of the outdoor unit to the capacity of each indoor unit (for example, Japanese Patent Application Laid-Open No.
294462).

Hereinafter, the conventional multi-room air conditioning system will be described with reference to the drawings.

FIG. 14 is a refrigeration cycle diagram of a conventional multi-chamber air conditioning system. In the multi-room air conditioning system, a plurality of, for example, two indoor units 52a, 5
2b. The outdoor unit 50 has a compressor 54 in which a capacity control operation is performed by an inverter 53.
Is installed. The refrigeration cycle includes the outdoor unit 50
A compressor 54, a four-way valve 55, an outdoor heat exchanger 56, a heating expansion mechanism 57, and a receiver 58 are sequentially extended into the branch unit 51, and a liquid-side refrigerant pipe 59 is installed in the branch unit 51. Branching is performed according to the number of units 52a and 52b. Liquid-side refrigerant pipe 60 branched
a and 60b are provided with a refrigerant circulation amount control device 61 and a cooling expansion mechanism 62, respectively.
b is the indoor heat exchanger 63 of the indoor units 52a and 52b.
a, 63b. This indoor heat exchanger 63a, 6
Solenoid valves 65a and 65b as on-off valves are provided in the branch unit 51 in the gas-side refrigerant pipes 64a and 64b from 3b, and then merge into the refrigerant pipe 66. This refrigerant pipe 66 is connected to the compressor 54 via the four-way valve 55. The heating and cooling expansion mechanisms 57, 62 are provided with expansion valves 67, 68.
An expansion valve bypass circuit is provided to bypass the expansion valves 67 and 68, respectively, and check valves 69 and 70 are provided in the bypass circuit. On the other hand, the refrigerant circulation amount control device 61 provided in the branch unit 51
Are electric flow regulating valves 71a, 71b provided in the liquid-side refrigerant branch pipes 60a, 60b, and the opening degree of the electric flow regulating valves 71a, 71b is set to the corresponding indoor unit 52.
15 is set according to the ratio between the capacities of the a and 52b and the capacity of the outdoor unit 50, thereby controlling the flow rate of the refrigerant flowing through each of the indoor units 52a and 52b.

In this multi-chamber air conditioning system, during cooling operation, the four-way valve 55 is set to the cooling side, and the refrigerant discharged from the compressor 54 flows through the four-way valve 55 to the outdoor heat exchanger 56, After being condensed here, it is adiabatically expanded by the expansion valve 68 through the electric flow rate regulating valves 71a and 71b, flows to the indoor heat exchangers 63a and 63b, cools and evaporates the room, and passes through the four-way valve 55. It is sucked into the compressor 16.

On the other hand, during the heating operation, the four-way valve 55 is set to the heating side, and the refrigerant discharged from the compressor 54 flows through the four-way valve 55 to the indoor heat exchangers 63a and 63b, where it is used for heating. After being condensed, it is adiabatically expanded by the expansion valve 67 through the check valve 70 and the electric flow regulating valves 71a and 71b, flows to the outdoor heat exchanger 56, evaporates there, and passes through the four-way valve 55 to the compressor 54. Inhaled.

Here, an indoor unit 52a having a capacity of 2HP and an indoor unit 52b having a capacity of 3HP are connected to an outdoor unit 50 having a capacity of 5HP (horsepower), and the maximum output frequency of the inverter 53 for driving the compressor 54 is 90 Hz. Consider the cooling operation in the case of. Indoor units 52a, 52b
If the two compressors ON signal is outputted required inverter output frequency P _f is expressed by the following equation.

[0009]

(Equation 1)

At this time, the valve openings of the electric flow control valves 71a and 71b are set to 50% and 72%, respectively, from FIG.

Further, when the compressor ON signal only from the indoor unit 52a is outputted required inverter output frequency P _f represented by the following formula.

[0012]

(Equation 2)

At this time, the valve openings of the electric flow regulating valves 71a and 71b are set to 50% and 0%, respectively.

As described above, this multi-chamber air conditioning system determines and controls the compressor capacity and the valve opening of the electric flow control valve in accordance with the capacity of the indoor unit. The refrigerant flow rate can be kept optimal.

[0015]

However, the above-mentioned conventional multi-room air conditioning system has the following problems.

That is, for example, in the case of heating operation, in each room where the indoor unit is installed, the room temperature is quickly increased with a large capacity at the start of heating, and as the room temperature approaches the set value, the capacity is gradually reduced to bring the room temperature close to the set value. Although it is necessary to keep it, as an example, if two indoor units of 2 hp and 3 hp are installed, even if the required capacity changes in each room, only approximately 2 hp and 3 hp can be obtained. When the room temperature rises above the set value, it turns off the thermostat and fully closes the motorized flow control valve connected to the indoor unit, and then turns on when the room temperature falls below the set value and opens the motorized flow control valve a predetermined amount. Repeated thermo-on and thermo-off such that the degree of temperature was reduced led to a decrease in comfort due to fluctuations in room temperature and an increase in power consumption. Also,
As a solution to this, even if the compressor capacity is changed in accordance with the sum of the required capacity of each room, each capacity can be obtained only at a ratio of 2: 3. In some cases, one room has insufficient capacity and the room temperature does not reach the set value, and the other room has excessive capacity and the room temperature exceeds the set value and is turned off. This leads to a decrease in power and an increase in power consumption.

In view of the above problems, the multi-chamber air conditioning system of the present invention does not complicate the configuration of a refrigeration cycle.
The purpose is to improve comfort and save energy by demonstrating the ability according to the required capacity of each of the multiple rooms.

Further, another multi-room air conditioning system of the present invention exhibits an improvement in comfort and energy savings by exerting the capacity according to the required capacity of each of the plurality of chambers while maintaining an optimum refrigeration cycle. It is intended for planning.

[0019]

In order to solve the above-mentioned problems, a multi-room air conditioning system according to the present invention has a capacity (frequency).
A single outdoor unit having a variable compressor, a four-way valve, an outdoor heat exchanger, a main motor-operated expansion valve that can be electrically controlled, and a plurality of indoor units having an indoor heat exchanger, A liquid-side branch pipe branching from a liquid-side main pipe in which the refrigerant liquid mainly flows and a gas-side branch pipe branching from a gas-side main pipe in which the refrigerant gas mainly flows in the outdoor unit and provided in the outdoor unit; A refrigeration cycle is configured by interposing an electric expansion valve capable of electrically controlling the valve opening in each of the liquid side branch pipes, and an indoor temperature setting capable of setting a desired indoor temperature in each of the indoor units. Means and an indoor temperature detecting means for detecting the indoor temperature, and a differential temperature calculating means for calculating a differential temperature between the set indoor temperature and the indoor temperature from the indoor temperature setting means and the indoor temperature detecting means, further comprising: Capacity determination means for determining the rated capacity of each machine and On / off determining means for determining whether each of the indoor units is operating or stopped is provided, a temperature range in which the temperature difference can be taken is divided into a plurality of temperature zones, and a rated capacity of each of the temperature zones and the indoor unit is provided. A load constant storage means for determining and storing a load constant corresponding to the indoor load for each indoor load; a valve initial opening storage means for determining and storing a valve initial opening for each rated capacity of the indoor unit; means,
A compressor capacity is calculated at predetermined intervals using data obtained from the capacity determination means, the on / off determination means, and the load constant storage means, and a capacity of the variable capacity (frequency) compressor is calculated based on the calculation result. When a plurality of the indoor units are in operation, the compressor and the operating room are operated at predetermined intervals using the data and the data obtained from the valve initial opening degree storage means. A valve opening control means for calculating the valve opening of each electric expansion valve connected to the motor and controlling the valve opening of the electric expansion valve based on the calculation result.

Another multi-chamber air conditioning system of the present invention has a variable capacity (frequency) compressor, a four-way valve, an outdoor heat exchanger, and a main motor-operated expansion valve which can be electrically controlled. A plurality of outdoor units and a plurality of indoor units having an indoor heat exchanger are provided in the outdoor unit, and a liquid-side branch pipe branching off a liquid-side main pipe through which a refrigerant liquid mainly flows and the outdoor unit are provided. The gas-side main pipe through which the refrigerant gas flows is connected via a branched gas-side branch pipe, and each of the liquid-side branch pipes is provided with an electrically-operable expansion valve capable of electrically controlling the valve opening. And each of the indoor units is provided with an indoor temperature setting means capable of setting a desired indoor temperature and an indoor temperature detecting means for detecting the indoor temperature, and is set from the indoor temperature setting means and the indoor temperature detecting means. Differential temperature calculator that calculates the difference between indoor temperature and indoor temperature Further provided with capacity determining means for determining the rated capacity of each of the indoor units, and on / off determining means for determining whether the indoor units are in operation or stopped for each of the indoor units, wherein a plurality of temperature ranges in which the differential temperature can be taken are provided. Load constant storage means for dividing and storing a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit, wherein the temperature difference calculating means and the capacity determining means are provided. A compressor for calculating a compressor capacity at predetermined intervals using data obtained from the on / off determining means and the load constant storage means, and controlling a capacity of the capacity (frequency) variable compressor based on the calculation result. Valve capacity control means is provided, and valve initial opening storage means is provided for determining and storing a valve initial opening for each electric expansion valve connected to each indoor unit for each combination of the number of operating indoor units and the rated capacity. When a plurality of the indoor units are in operation, the indoor unit is connected to the operating indoor unit at predetermined intervals using the data and the data of the valve initial opening obtained from the valve initial opening storage means. A valve opening control means for calculating the valve opening of each electric expansion valve and controlling the valve opening of the electric expansion valve based on the calculation result is provided.

Another multi-chamber air conditioning system of the present invention has a variable capacity (frequency) compressor, a four-way valve, an outdoor heat exchanger, and a main motor-operated expansion valve which can be electrically controlled. A plurality of outdoor units and a plurality of indoor units having an indoor heat exchanger are provided in the outdoor unit, and a liquid-side branch pipe branching off a liquid-side main pipe through which a refrigerant liquid mainly flows and the outdoor unit are provided. The gas-side main pipe through which the refrigerant gas flows is connected via a branched gas-side branch pipe, and each of the liquid-side branch pipes is provided with an electrically-operable expansion valve capable of electrically controlling the valve opening. And each of the indoor units is provided with an indoor temperature setting means capable of setting a desired indoor temperature and an indoor temperature detecting means for detecting the indoor temperature, and is set from the indoor temperature setting means and the indoor temperature detecting means. Differential temperature calculator that calculates the difference between indoor temperature and indoor temperature Further provided with capacity determining means for determining the rated capacity of each of the indoor units, and on / off determining means for determining whether the indoor units are in operation or stopped for each of the indoor units, wherein a plurality of temperature ranges in which the differential temperature can be taken are provided. Load constant storage means for dividing and storing a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit, wherein the temperature difference calculating means and the capacity determining means are provided. A compressor for calculating a compressor capacity at predetermined intervals using data obtained from the on / off determining means and the load constant storage means, and controlling a capacity of the capacity (frequency) variable compressor based on the calculation result. A valve capacity control means, and a valve initial opening calculating means for calculating a valve initial opening for each electric expansion valve connected to each indoor unit by an approximate expression using the data. Is operating, the valve opening of each electric expansion valve connected to the operating indoor unit is performed at predetermined intervals using the data and the data of the valve initial opening obtained by the valve initial opening calculating means. And a valve opening control means for controlling the valve opening of the electric expansion valve based on the calculation result.

Further, another multi-chamber air conditioning system according to the present invention is provided with superheat degree detecting means for detecting the superheat degree of the refrigerant sucked into the variable capacity (frequency) compressor at predetermined intervals.
The valve opening of the main motor-operated expansion valve connected between the outdoor heat exchanger and the motor-operated expansion valve connected to the liquid-side branch pipe is determined in accordance with the superheat degree data detected by the superheat degree detection means. A valve opening determining means is provided, and the valve opening controlling means controls the valve opening.

Further, another multi-chamber air conditioning system of the present invention reduces the valve opening of a main motor-operated expansion valve connected between an outdoor heat exchanger and a motor-operated expansion valve connected to a liquid side branch pipe. There is provided a valve opening determining means for determining the valve opening corresponding to the compressor capacity calculated by the machine capacity controlling means, and the valve opening controlling means controls the valve opening.

Further, another multi-chamber air conditioning system according to the present invention comprises a discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the variable capacity (frequency) compressor at predetermined intervals, and compressing the discharge temperature. Compressor discharge temperature determining means for determining in accordance with the compressor capacity calculated by the capacity control means,
The valve opening of the main electric expansion valve connected between the outdoor heat exchanger and the electric expansion valve connected to the liquid side branch pipe is determined in accordance with the discharge temperature data detected by the discharge temperature detecting means. A valve opening determining means is provided, and the valve opening controlling means controls the valve opening.

[0025]

The present invention has the following functions by the above means.

That is, each of the indoor units is provided with an indoor temperature setting means for setting a desired indoor temperature and an indoor temperature detecting means for detecting the indoor temperature, and the indoor temperature setting means and the indoor temperature detecting means are used for setting. A differential temperature calculating means for calculating a temperature difference between the indoor temperature and the indoor temperature; a capacity determining means for determining a rated capacity of each of the indoor units; and determining whether each of the indoor units is operating or stopped. On / off determining means for dividing a temperature range in which the temperature difference can be taken into a plurality of temperature zones, and determining and storing a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant storage means is provided, and a valve initial opening storage means for determining and storing a valve initial opening for each rated capacity of the indoor unit is provided, wherein the differential temperature calculating means, the capacity determining means, and the on / off determining means are provided. Compressor capacity control means for calculating a compressor capacity at predetermined intervals using data obtained from the load constant storage means and controlling the capacity of the capacity (frequency) variable compressor based on the calculation result. When a plurality of the indoor units are in operation, using the data and the data obtained from the valve initial opening storage means, each of the electric expansion valves connected to the operating indoor unit at predetermined intervals is used. By calculating the valve opening and providing valve opening control means for controlling the valve opening of the electric expansion valve based on the calculation result, the compressor frequency is controlled in accordance with the total required capacity of each room. In addition, since the degree of opening of each electric expansion valve is determined according to the load of each room, necessary capacity can be allocated to necessary rooms, and improvement in comfort and energy saving can be achieved.

Each of the indoor units is provided with an indoor temperature setting means for setting a desired indoor temperature and an indoor temperature detecting means for detecting the indoor temperature. The indoor temperature setting means and the indoor temperature detecting means are used for setting. A differential temperature calculating means for calculating a temperature difference between the indoor temperature and the indoor temperature; a capacity determining means for determining a rated capacity of each of the indoor units; and determining whether each of the indoor units is operating or stopped. On / off determining means for dividing a temperature range in which the temperature difference can be taken into a plurality of temperature zones, and determining and storing a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant storage means for calculating a compressor capacity at predetermined intervals using data obtained from the temperature difference calculating means, the capacity determining means, the on / off determining means, and the load constant storing means; A compressor capacity control means for controlling the capacity of the variable capacity (frequency) compressor based on the calculation result is provided, and the electric motor connected to each indoor unit for each combination of the number of operating indoor units and the rated capacity is provided. Valve initial opening storage means for determining and storing a valve initial opening for each expansion valve is provided, and when a plurality of indoor units are in operation, the data and a valve obtained from the valve initial opening storing means are provided. Using the data of the initial opening degree, the valve opening degree of each electric expansion valve connected to the operating indoor unit is calculated every predetermined cycle, and the valve opening degree of the electric expansion valve is controlled based on the calculation result. By providing the valve opening control means, it is necessary to control the compressor frequency according to the sum of the required capacity of each room, and to determine the opening of each electric expansion valve according to the load of each room. The capacity can be allocated to the required room, and the valve Since determined for each combination of the number of operating units and their rated capacity of the machine, it is capable of capacity control more finely accuracy can be improved and energy saving comfort.

Each of the indoor units is provided with an indoor temperature setting means for setting a desired indoor temperature and an indoor temperature detecting means for detecting the indoor temperature. The indoor temperature setting means and the indoor temperature detecting means are used for setting. A differential temperature calculating means for calculating a temperature difference between the indoor temperature and the indoor temperature; a capacity determining means for determining a rated capacity of each of the indoor units; and determining whether each of the indoor units is operating or stopped. On / off determining means for dividing a temperature range in which the temperature difference can be taken into a plurality of temperature zones, and determining and storing a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant storage unit is provided, and a compressor capacity is calculated at predetermined intervals using data obtained from the differential temperature calculation unit, the capacity determination unit, the on / off determination unit, and the load constant storage unit. A compressor capacity control means for controlling the capacity of the variable capacity (frequency) compressor based on the calculation result, and using an approximation formula using the data, for each electric expansion valve connected to each indoor unit. A valve initial opening calculating means for calculating a valve initial opening is provided, and when a plurality of the indoor units are operating, the data and the valve initial opening data obtained from the valve initial opening calculating means are provided. A valve opening control means for calculating a valve opening of each electric expansion valve connected to the operating indoor unit for each predetermined cycle, and controlling the valve opening of the electric expansion valve based on the calculation result. By providing this, the initial valve opening is determined by an approximate expression for each combination of the number of operating indoor units and the rated capacity thereof, so that more detailed and high-precision capacity control is possible, and improvement of comfort and energy saving are achieved. be able to. Further, since a table of the valve initial opening is not required, it is not necessary to increase the capacity of the storage circuit even when the number of indoor units further increases.

Further, a superheat degree detecting means for detecting the superheat degree of the refrigerant sucked into the variable capacity (frequency) compressor at predetermined intervals is provided, and the electric expansion connected to the outdoor heat exchanger and the liquid side branch pipe is provided. Valve opening degree determining means for determining the valve opening degree of the main motor-operated expansion valve connected between the valves in accordance with the superheat degree data detected by the superheat degree detecting means is provided, and the valve opening degree control means By controlling the valve opening degree to control the superheat degree of the refrigerant drawn into the compressor to a predetermined value, it is possible to improve comfort and save energy while controlling the refrigeration cycle more finely and optimally. it can.

The valve opening of the main motor-operated expansion valve connected between the outdoor heat exchanger and the motor-operated expansion valve connected to the liquid side branch pipe corresponds to the compressor capacity calculated by the compressor capacity control means. A valve opening determining means for determining the valve opening of the main electric expansion valve corresponding to the compressor frequency by controlling the valve opening by the valve opening control means. Without increasing the complexity of the refrigeration cycle, it is possible to improve comfort and save energy while maintaining the refrigeration cycle optimally.

Also, a discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the variable capacity (frequency) compressor at predetermined intervals, and a discharge temperature corresponding to the compressor capacity calculated by the compressor capacity control means. The compressor discharge temperature determining means is provided for determining the opening degree of the main electric expansion valve connected between the outdoor heat exchanger and the electric expansion valve connected to the liquid side branch pipe. By providing a valve opening determining means for determining in accordance with the detected discharge temperature data, the valve opening control means controls the valve opening to control the compressor discharge temperature to be maintained at a predetermined value. Therefore, it is possible to improve comfort and save energy while controlling the refrigeration cycle more precisely and optimally without complicating the configuration.

[0032]

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

FIG. 1 is a refrigeration cycle diagram of a first embodiment of the multi-room air conditioning system according to the present invention. In addition,
In this embodiment, one outdoor unit 1 and three indoor units 2
The case where a, b, and c are connected will be described.

In FIG. 1, an outdoor unit 1 is provided with an inverter-driven variable frequency compressor 3 (hereinafter simply referred to as a compressor), an outdoor heat exchanger 4, and a four-way valve 5 for switching between cooling and heating. The indoor heat exchangers 6a, 6b, 6c are provided in the units 2a, 2b, 2c, respectively. The outdoor unit 1 and the indoor units 2a, 2b, 2c are connected to liquid side branch pipes 8a, 8 branched from the liquid side main pipe 7 provided in the outdoor unit 1.
b, 8c and gas side branch pipes 10a, 10b, 10c branched from a gas side main pipe 9 provided in the outdoor unit 1. The liquid-side branch pipes 8a, 8b, and 8c are provided with electric expansion valves 11a, 11b, and 11c each of which can be pulse-controlled by using a stepping motor, and a refrigerant liquid is provided on the liquid-side main pipe 7. A receiver 12 capable of storing is provided.
A main motor-operated expansion valve 13 is provided to maintain the receiver 12 at an intermediate pressure for cooling and heating. Further, a bypass circuit 15 for connecting the receiver 12 and the suction pipe 14 to the compressor 3 is provided, and the bypass circuit 15 is provided with an auxiliary throttle 16. Each of the indoor units 2a, 2b, and 2c has an indoor temperature sensor 17a, 17b, and 17c for detecting the room temperature of the room in which each indoor unit is installed, and an operation mode (cooling or heating) desired by the occupant and the room temperature. Operation setting circuits 18a, 18b, and 18c capable of setting operation and stop are provided. The suction pipe 14 is provided with a suction temperature sensor 19 for detecting the temperature of the refrigerant flowing therethrough.
5 is provided with a saturation temperature sensor 20 for detecting the saturation temperature of the refrigerant flowing through the suction pipe 14.

In this refrigeration cycle, during cooling, the refrigerant discharged from the compressor 3 flows from the four-way valve 5 to the outdoor heat exchanger 4, where it exchanges heat with outdoor air to condense and liquefy.
The pressure is reduced by the main electric expansion valve 13 to an intermediate pressure. And
A part of the liquid refrigerant is stored in the receiver 12, and the rest branches to the liquid side branch pipes 8a, 8b, 8c. Electric expansion valve 11a,
Since the valve opening of the valves 11b and 11c is controlled by a control method described later so as to be in accordance with the load of each room, the refrigerant also has a low pressure at a flow rate corresponding to each load, and the indoor heat exchange is performed. After flowing to the devices 6a, 6b, and 6c and evaporating, the gas passes through the gas-side branch pipes 10a, 10b, and 10c, passes through the gas-side main pipe 9, and the four-way valve 5, and is again sucked into the compressor 3.
Also, a very small amount of liquid refrigerant flows from the receiver 12 to the bypass circuit 15, and is decompressed by the auxiliary throttle 16, and
Flows to 4. At this time, since the refrigerant that has passed through the auxiliary throttle 16 is a gas-liquid two-phase flow and the pressure is substantially equal to the refrigerant flowing through the suction pipe 14, the saturation temperature sensor 20 can detect the saturation temperature. The compressor frequency is determined by a control method described later according to the total load.

At the time of heating, the refrigerant discharged from the compressor 3
The four-way valve 5 is switched so that the gas-side branch pipe 10
a, 10b, and 10c, and the indoor heat exchangers 6a and 6c
b, 6c to condense and liquefy, and the liquid side branch pipes 8a, 8
The pressure is reduced by the electric expansion valves 11a, 11b, and 11c on b and 8c to an intermediate pressure. Electric expansion valves 11a, 11b, 11
The valve opening of c is controlled by a control method described later to be an opening corresponding to the load of each room as in the case of cooling, so that the refrigerant is also supplied to the indoor heat exchanger at a flow rate corresponding to each load. 6a, 6b and 6c. The intermediate-pressure refrigerant is partially stored in the receiver 12, and the remaining refrigerant is reduced in pressure by the main electric expansion valve 13 to become a low pressure, flows through the outdoor heat exchanger 4 and evaporates, and then is evaporated. And is sucked into the compressor 3 again. Also, a very small amount of liquid refrigerant flows from the receiver 12 to the bypass circuit 15, is depressurized by the auxiliary throttle 16, and flows to the suction pipe 14. As in the case of cooling, the refrigerant that has passed through the auxiliary throttle 16 is a gas-liquid two-phase flow, and the pressure is almost equal to that of the refrigerant flowing through the suction pipe 14. Therefore, the saturation temperature sensor 20 can detect the saturation temperature. Further, the compressor frequency is determined by a control method described later according to the total load as in the case of cooling.

Next, a method of controlling the compressor frequency and the electric expansion valve opening will be described. Figure 2 is a block diagram showing the control flow of the compressor frequency and motor-operated expansion valve opening, FIG 3 is a temperature zone division diagram of differential temperature ΔT between the set temperature T _s and the room temperature T _r, 4 superheat degree SH FIG. 7 is a relationship diagram between the main electric expansion valve and the opening change amount of the main electric expansion valve.

First, in the indoor unit 2a, the output of the indoor temperature sensor 17a is sent from the indoor temperature detecting circuit 21 to the temperature difference calculating circuit 22 as a temperature signal.
Then, the set temperature and the operation mode set by the operation setting circuit 18a are discriminated and sent to the temperature difference calculating circuit 22, where the temperature difference ΔT (= T _r −T _s ) is calculated, and the load shown in FIG. The value is converted into a number Ln value and is used as a differential temperature signal. For example, if T _r = 27.3 ° C. and T _s = 26 ° C. during the cooling operation, Ln = 6 at the temperature difference ΔT = 1.3 ° C. Further, the ON-OFF determination circuit 24 determines whether the indoor unit 2a is set to the operation (ON) or stop (OFF) set by the operation setting circuit 18a.
Further, the rated capacity of the indoor unit 2a is stored in the rated capacity storage circuit 25, and the rated capacity signal, the differential temperature signal, the operation mode signal, and the ON / OFF determination signal are transmitted to the signal transmission circuit 26.
The signal is sent to the signal receiving circuit 27 of the outdoor unit 1. Indoor unit 2b,
A similar signal is sent from 2c to the signal receiving circuit 27.
The signal received by the signal receiving circuit 27 is sent to a compressor frequency calculating circuit 28 and an expansion valve opening calculating circuit 29. However,
If a different operation mode signal exists, the operation mode of the indoor unit that started operation first has priority, and the indoor unit in the different operation mode is regarded as stopped and turned ON-OFF.
The discrimination signal always sends OFF.

In the compressor frequency calculation circuit 28, the indoor unit 2
a, the rated capacity signal of each of 2b, 2c, the differential temperature signal,
The load constant is read from the load constant table 30 shown in the following (Table 1) from the operation mode signal and the ON-OFF determination signal, and the sum of the load constants is multiplied by a constant to determine the frequency of the compressor 3.

[0040]

[Table 1]

As an example, a case where the signals from the indoor units 2a, 2b, 2c are as shown in Table 2 below will be described.

[0042]

[Table 2]

From (Table 1) and (Table 2), the indoor units 2a, 2a
The load constants of b and 2c are 1.5, 1.0 and 1.9, respectively.
Therefore, the frequency Hz of the compressor 3 is given by: Hz = A × (1.5 + 1.0 + 1.9) = A × 4.4 where A is a constant, and the calculation result is used as a frequency signal as a compressor drive circuit (FIG. (Not shown) to control the frequency of the compressor 3. Thereafter, the rated capacity signal, the differential temperature signal, the operation mode signal, the O
Calculation is performed based on the N-OFF determination signal, and the calculation result is sent to a compressor drive circuit (not shown) as a frequency signal to control the frequency of the compressor 3.

Similarly, in the expansion valve opening calculation circuit 29, the load shown in Table 1 is obtained from the rated capacity signal, the differential temperature signal, the operation mode signal, and the ON / OFF discrimination signal of each of the indoor units 2a, 2b, 2c. The load constant is selected from the constant table 30, and is read from the valve initial opening table 31 for each rated capacity shown in the following (Table 3) from the rated capacity of each of the indoor units 2a, 2b, and 2c. Note that the valve initial opening is determined so that each indoor unit can perform predetermined capacity control even with a combination of indoor units having different rated capacities.

[0045]

[Table 3]

The valve opening of the electric expansion valves 11a, 11b, 11c is obtained by dividing each load constant by a predetermined value of the load constant and multiplying the result by the initial valve opening. As in the case of the compressor frequency calculation example, the case where the signals from the indoor units 2a, 2b, and 2c are (Table 2) will be described.

The (load constant / predetermined load constant) of the indoor units 2a, 2b and 2c are (1.5 / 2.0) and (1.0
/2.5) and (1.9 / 3.2), and the initial valve openings are 100, 130 and 180, respectively. Therefore,
The valve opening degree of the electric expansion valves 11a, 11b, 11c is 75,
52, 107 (rounded to one decimal place).
This calculation result is sent to an expansion valve drive circuit (not shown) as an expansion valve opening signal. Therefore, the electric expansion valve 11
The valve opening degrees of a, 11b, and 11c are 75 pulses, 5
2 pulses, 107 pulses, and thereafter, every predetermined period,
The valve openings of the electric expansion valves 11a, 11b, 11c are calculated from the temperature difference signal, the operation mode signal, and the ON-OFF determination signal,
These calculation results are sent to an expansion valve drive circuit (not shown) as an expansion valve opening signal. Also, the suction temperature sensor 19
Is sent from the suction temperature detection circuit 32 to the superheat degree calculation circuit 33 as a temperature signal, and the output of the saturation temperature sensor 20 is sent from the saturation temperature detection circuit 34 to the superheat degree calculation circuit 33 as a temperature signal. SH (= suction temperature−saturation temperature) is calculated and sent to the expansion valve opening calculation circuit 29.
In the expansion valve opening calculating circuit 29, the sent superheat SH
, The number of valve opening change pulses is calculated as shown in FIG. 4 and sent to a drive circuit (not shown) of the main electric expansion valve 13 to be controlled.

Although the above description has been made mainly for cooling, the same can be applied to heating.

As described above, since the compressor frequency is controlled in accordance with the sum of the required capacity of each room, and the opening degree of each electric expansion valve is determined in accordance with the load in each room, necessary capacity is required. The superheat degree of the refrigerant suctioned by the compressor is maintained at a predetermined value by the main electric expansion valve connected between the outdoor heat exchanger and the electric expansion valve connected to the liquid side branch pipe at the same time. Is controlled as follows. Therefore, it is possible to improve comfort and save energy while controlling the refrigeration cycle finely and optimally. Next, the second embodiment of the present invention
Will be described with reference to the drawings. The refrigeration cycle in the second embodiment is the same as that in the first embodiment shown in FIG.
FIG. 5 is a block diagram showing the flow of control of the compressor frequency and the electric expansion valve opening in the second embodiment of the present invention.
This figure differs from FIG. 2 which is a block diagram of the first embodiment, in that the number of operating indoor units and the rated capacity thereof are replaced with the valve initial opening degree table 31 determined corresponding to the rated capacity of the indoor units. That is, a valve initial opening table 35 determined for each combination is used. The valve initial opening table 35 is represented as shown in the following (Table 4).

[0050]

[Table 4]

The electric expansion valves 11a, 11b, 11
The valve opening of c is obtained by multiplying the value obtained by dividing each load constant by a predetermined value of the load constant and the initial valve opening.

As described above, since the initial valve opening is determined for each combination of the number of operating indoor units and the rated capacity thereof, more detailed and high-precision capacity control is possible, and improvement in comfort and energy saving are achieved. be able to.

Next, a third embodiment of the present invention will be described with reference to the drawings. The refrigeration cycle in the third embodiment is the same as that in the first embodiment shown in FIG. FIG. 6 is a block diagram showing the flow of control of the compressor frequency and the electric expansion valve opening in the third embodiment of the present invention. This figure differs from the first and second embodiments in that the valve initial opening table 31 and the valve initial opening table 35 for each rated capacity are not used. That is, the initial valve opening is calculated by the expansion valve opening calculation circuit 29 from the number of operating indoor units and the respective rated capacities.
It is calculated by an approximate expression.

For example, the initial valve opening of the indoor unit 2a is represented by f (the rated capacity of the indoor unit 2a, the number of operating units, and the rated capacity of the indoor unit in operation) (f is a function). Indoor unit 2
The same applies to b and 2c. The valve opening of the electric expansion valves 11a, 11b, 11c is obtained by multiplying the load constant by dividing the load constant by a predetermined value of the load constant by the valve initial opening.

As described above, since the initial valve opening is determined by the approximate expression for each combination of the number of operating indoor units and the rated capacity thereof, more precise and high-precision capability control is possible.
It is possible to improve comfort and save energy. Further, since a table of the valve initial opening is not required, it is not necessary to increase the capacity of the storage circuit even when the number of indoor units further increases. In the above embodiment, the indoor unit 2
The initial valve opening of a is represented by f (the rated capacity of the indoor unit 2a, the number of operating units, and the rated capacity of the indoor unit in operation), but f (the rated capacity of the indoor unit 2a, the rated capacity of the indoor unit 2a). The accuracy can be further improved by creating an approximate expression as the load constant, the number of operating units, and the rated capacity of the indoor unit during operation (the same applies to the indoor units 2b and 2c).

Next, a fourth embodiment will be described. FIG.
FIG. 8 is a refrigeration cycle diagram in a fourth embodiment of the multi-room air conditioning system of the present invention. This refrigeration cycle differs from the first to third embodiments in that there is no circuit or sensor for detecting the degree of superheating of the refrigerant flowing through the suction pipe 14. That is, the refrigeration cycle of FIG. 7 does not include the bypass circuit 15, the saturation temperature sensor 20, and the suction temperature sensor 19 of the refrigeration cycle of FIG. FIG. 8 is a block diagram showing the flow of control of the compressor frequency and the electric expansion valve opening of the present embodiment, and FIG. 9 is a diagram showing the relationship between the compressor frequency and the valve opening of the main electric expansion valve.

The control method of the compressor frequency and the electric expansion valve opening in this embodiment will be described. In FIG. 8, the compressor units 2a, 2b,
2c, the load constant is read from the load constant table 30 shown in (Table 1) from the rated capacity signal, the differential temperature signal, the operation mode signal, and the ON-OFF discrimination signal, and the sum of the load constants is multiplied by a constant. The third embodiment is the same as the first to third embodiments up to the point of determining the third frequency. The calculation result is sent as a frequency signal to a compressor drive circuit (not shown) to control the frequency of the compressor 3 and to the expansion valve opening calculation circuit 29. Thereafter, at predetermined intervals, calculations are performed based on the rated capacity signal, the differential temperature signal, the operation mode signal, and the ON / OFF determination signal of the indoor units 2a, 2b, and 2c, and the calculation result is used as a frequency signal as a compressor drive circuit (FIG. (Not shown) to control the frequency of the compressor 3 and also to the expansion valve opening calculation circuit 29.

Similarly, in the expansion valve opening calculation circuit 29, the load shown in Table 1 is obtained from the rated capacity signal, the differential temperature signal, the operation mode signal, and the ON-OFF discrimination signal of the indoor units 2a, 2b, 2c. The load constant is selected from the constant table 30, and the valve initial opening is read from the valve initial opening table 31 for each rated capacity shown in (Table 3) from the respective rated capacities of the indoor units 2a, 2b, 2c. Electric expansion valve 11
The valve openings a, 11b, and 11c are obtained by multiplying a value obtained by dividing each load constant by a predetermined value of the load constant and an initial valve opening. The expansion valve opening calculation circuit 29 calculates the opening of the main electric expansion valve 13 corresponding to the frequency signal sent from the compressor frequency calculation circuit 28. Here, the first
Similar to the embodiment, the case where the signals from the indoor units 2a, 2b, and 2c are (Table 2) will be specifically described.

The (load constant / predetermined load constant) of the indoor units 2a, 2b and 2c are (1.5 / 2.0) and (1.0
/2.5) and (1.9 / 3.2), and the initial valve opening is 1.0, 1.2 and 1.4, respectively. Therefore,
The valve opening degree of the electric expansion valves 11a, 11b, 11c is 75,
52, 107 (rounded to one decimal place).
Further, the valve opening of the main electric expansion valve 13 is calculated from the frequency transmitted from the compressor frequency calculation circuit 28 using the relationship shown in FIG.

Considering the case where the frequency transmitted from the compressor frequency calculation circuit 28 is 75 Hz, the valve opening of the main electric expansion valve 13 is 400 pulses from FIG. This calculation result is sent to an expansion valve drive circuit (not shown) as an expansion valve opening signal. Thereafter, the compressor frequency calculation circuit 2
8, the main motor-operated expansion valve 1
3, and the rated capacity signal, the differential temperature signal, the operation mode signal, and the O of each of the indoor units 2a, 2b, and 2c.
From the N-OFF determination signal, the electric expansion valves 11a, 11b, 1
1c is calculated, and the calculation result is sent to an expansion valve drive circuit (not shown) as an expansion valve opening signal.

As described above, since the compressor frequency is controlled in accordance with the sum of the required capacity of each room and the opening degree of each electric expansion valve is determined in accordance with the load in each room, necessary capacity is required. Can be allocated to different rooms, and at the same time, the valve opening of the main electric expansion valve is determined according to the compressor frequency. And energy saving can be achieved.

Next, a fifth embodiment will be described. FIG.
0 is a refrigeration cycle diagram in the fifth embodiment of the multi-room air conditioning system of the present invention. This refrigeration cycle differs from the fourth embodiment in that a discharge temperature sensor 37 for detecting the temperature of the refrigerant flowing through the discharge pipe 36 is provided. FIG. 11 is a block diagram showing the flow of control of the compressor frequency and the electric expansion valve opening of the present embodiment, and FIG. 12 is a diagram showing the relationship between the compressor frequency and the valve opening of the main electric expansion valve.

A method of controlling the compressor frequency and the degree of opening of the electric expansion valve in this embodiment will be described. In FIG. 11, the indoor units 2a, 2b,
2c, the load constant is read from the load constant table 30 shown in (Table 1) from the rated capacity signal, the differential temperature signal, the operation mode signal, and the ON-OFF discrimination signal, and the sum of the load constants is multiplied by a constant. The third embodiment is the same as the first to fourth embodiments up to the point of determining the frequency. The calculation result is sent as a frequency signal to a compressor drive circuit (not shown) to control the frequency of the compressor 3 and to the discharge temperature calculation circuit 38. Thereafter, at predetermined intervals, calculations are performed based on the rated capacity signal, the differential temperature signal, the operation mode signal, and the ON / OFF determination signal of the indoor units 2a, 2b, and 2c, and the calculation result is used as a frequency signal as a compressor drive circuit (FIG. (Not shown) to control the frequency of the compressor 3 and also to the discharge temperature calculation circuit 38.

Similarly, in the expansion valve opening calculating circuit 29, the load shown in Table 1 is obtained from the rated capacity signal, the differential temperature signal, the operation mode signal, and the ON / OFF discrimination signal of the indoor units 2a, 2b, 2c. The load constant is selected from the constant table 30, and the valve initial opening is read from the valve initial opening table 31 for each rated capacity shown in (Table 3) from the respective rated capacities of the indoor units 2a, 2b, 2c. Electric expansion valve 11
The valve openings a, 11b, and 11c are obtained by multiplying a value obtained by dividing each load constant by a predetermined value of the load constant and an initial valve opening. The discharge temperature calculating circuit 38 calculates a target discharge temperature corresponding to the frequency signal sent from the compressor frequency calculating circuit 28 and sends it to the discharge temperature difference calculating circuit 40 as a temperature signal. The output is sent from the discharge temperature detection circuit 39 to the discharge temperature difference calculation circuit 40 as a temperature signal, where the discharge temperature difference (= discharge temperature−
The target discharge temperature) ΔTdis is calculated and sent to the expansion valve opening calculation circuit 29. The expansion valve opening calculation circuit 29 calculates the valve opening change pulse number according to the received discharge temperature difference ΔTdis as shown in FIG.
To a driving circuit (not shown).

As described above, since the compressor frequency is controlled in accordance with the sum of the required capacity of each room, and the opening degree of each electric expansion valve is determined in accordance with the load in each room, necessary capacity is required. To control the compressor discharge temperature to a predetermined value at the same time, to improve comfort and save energy while keeping the refrigeration cycle more optimal without complicating the structure. be able to.

[0066]

As is clear from the above embodiment, the multi-room air conditioning system according to the present invention has an indoor temperature setting means for setting a desired indoor temperature and an indoor temperature for detecting the indoor temperature in each of the indoor units. Detecting means, a differential temperature calculating means for calculating a difference between the set indoor temperature and the indoor temperature from the indoor temperature setting means and the indoor temperature detecting means, and further determining a rated capacity of each of the indoor units. A capacity discriminating means and on / off discriminating means for discriminating whether each of the indoor units is in operation or stopped is provided, a temperature range in which the temperature difference can be taken is divided into a plurality of temperature zones, and each of the temperature zones and the indoor A load constant storage means for determining and storing a load constant corresponding to the indoor load is provided for each rated capacity of the unit, and a valve initial opening storage means for determining and storing a valve initial opening for each rated capacity of the indoor unit is provided, Said The compressor capacity is calculated at predetermined intervals using data obtained from the temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means, and the capacity (frequency) variable type is calculated based on the calculation result. Compressor capacity control means for controlling the capacity of the compressor is provided, and when a plurality of the indoor units are in operation, the data and the data obtained from the valve initial opening degree storage means are used at predetermined intervals. By calculating the valve opening of each electric expansion valve connected to the operating indoor unit and providing valve opening control means for controlling the valve opening of the electric expansion valve based on the calculation result, each room is provided. To control the compressor frequency according to the sum of the required capacity of each, and to determine the opening of each electric expansion valve according to the load of each room, it is possible to allocate the necessary capacity to the necessary room,
It is possible to improve comfort and save energy.

Further, each of the indoor units is provided with an indoor temperature setting means for setting a desired indoor temperature and an indoor temperature detecting means for detecting the indoor temperature, and the indoor temperature setting means and the indoor temperature detecting means are used for setting. A differential temperature calculating means for calculating a temperature difference between the indoor temperature and the indoor temperature; a capacity determining means for determining a rated capacity of each of the indoor units; and determining whether each of the indoor units is operating or stopped. On / off determining means for dividing a temperature range in which the temperature difference can be taken into a plurality of temperature zones, and determining and storing a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant storage unit is provided, and a compressor capacity is calculated at predetermined intervals using data obtained from the differential temperature calculation unit, the capacity determination unit, the on / off determination unit, and the load constant storage unit. A compressor capacity control means for controlling the capacity of the variable capacity (frequency) compressor based on the calculation result is provided, and the electric motor connected to each indoor unit for each combination of the number of operating indoor units and the rated capacity is provided. Valve initial opening storage means for determining and storing a valve initial opening for each expansion valve is provided, and when a plurality of indoor units are in operation, the data and a valve obtained from the valve initial opening storing means are provided. Using the data of the initial opening degree, the valve opening degree of each electric expansion valve connected to the operating indoor unit is calculated every predetermined cycle, and the valve opening degree of the electric expansion valve is controlled based on the calculation result. By providing the valve opening control means, it is necessary to control the compressor frequency according to the sum of the required capacity of each room, and to determine the opening of each electric expansion valve according to the load of each room. The capacity can be allocated to the required room, and the valve Since determined for each combination of the number of operating units and their rated capacity of the machine, it is capable of capacity control more finely accuracy can be improved and energy saving comfort.

Each of the indoor units is provided with an indoor temperature setting means capable of setting a desired indoor temperature and an indoor temperature detecting means for detecting the indoor temperature. A differential temperature calculating means for calculating a temperature difference between the indoor temperature and the indoor temperature; a capacity determining means for determining a rated capacity of each of the indoor units; and determining whether each of the indoor units is operating or stopped. On / off determining means for dividing a temperature range in which the temperature difference can be taken into a plurality of temperature zones, and determining and storing a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant storage unit is provided, and a compressor capacity is calculated at predetermined intervals using data obtained from the differential temperature calculation unit, the capacity determination unit, the on / off determination unit, and the load constant storage unit. A compressor capacity control means for controlling the capacity of the variable capacity (frequency) compressor based on the calculation result, and using an approximation formula using the data, for each electric expansion valve connected to each indoor unit. A valve initial opening calculating means for calculating a valve initial opening is provided, and when a plurality of the indoor units are operating, the data and the valve initial opening data obtained from the valve initial opening calculating means are provided. A valve opening control means for calculating a valve opening of each electric expansion valve connected to the operating indoor unit for each predetermined cycle, and controlling the valve opening of the electric expansion valve based on the calculation result. By providing this, the initial valve opening is determined by an approximate expression for each combination of the number of operating indoor units and the rated capacity thereof, so that more detailed and high-precision capacity control is possible, and improvement of comfort and energy saving are achieved. be able to. Further, since a table of the valve initial opening is not required, it is not necessary to increase the capacity of the storage circuit even when the number of indoor units further increases.

Further, a superheat degree detecting means for detecting the superheat degree of the refrigerant drawn into the variable capacity (frequency) compressor at predetermined intervals is provided, and the electric expansion connected to the outdoor heat exchanger and the liquid side branch pipe is provided. Valve opening degree determining means for determining the valve opening degree of the main motor-operated expansion valve connected between the valves in accordance with the superheat degree data detected by the superheat degree detecting means is provided, and the valve opening degree control means By controlling the valve opening degree to control the superheat degree of the refrigerant drawn into the compressor to a predetermined value, it is possible to improve comfort and save energy while controlling the refrigeration cycle more finely and optimally. it can.

The valve opening of the main motor-operated expansion valve connected between the outdoor heat exchanger and the motor-operated expansion valve connected to the liquid side branch pipe corresponds to the compressor capacity calculated by the compressor capacity control means. A valve opening determining means for determining the valve opening of the main electric expansion valve corresponding to the compressor frequency by controlling the valve opening by the valve opening control means. Without increasing the complexity of the refrigeration cycle, it is possible to improve comfort and save energy while maintaining the refrigeration cycle optimally.

A discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the variable capacity (frequency) compressor at predetermined intervals, and a discharge temperature corresponding to the compressor capacity calculated by the compressor capacity control means. The compressor discharge temperature determining means is provided for determining the opening degree of the main electric expansion valve connected between the outdoor heat exchanger and the electric expansion valve connected to the liquid side branch pipe. By providing a valve opening determining means for determining in accordance with the detected discharge temperature data, the valve opening control means controls the valve opening to control the compressor discharge temperature to be maintained at a predetermined value. Therefore, it is possible to improve comfort and save energy while controlling the refrigeration cycle more precisely and optimally without complicating the configuration.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram in a first embodiment of a multi-room air conditioning system of the present invention.

FIG. 2 is a control block diagram of a compressor frequency and an electric expansion valve opening degree in the embodiment.

FIG. 3 is a temperature zone division diagram of the differential temperature ΔT.

FIG. 4 is a relationship diagram between the degree of superheat SH and the amount of change in the opening degree of the main electric expansion valve.

FIG. 5 is a control block diagram of a compressor frequency and an electric expansion valve opening in a second embodiment of the multi-chamber air conditioning system of the present invention.

FIG. 6 is a control block diagram of a compressor frequency and an electric expansion valve opening in a third embodiment of the multi-chamber air conditioning system of the present invention.

FIG. 7 is a refrigeration cycle diagram in a fourth embodiment of the multi-chamber air conditioning system of the present invention.

FIG. 8 is a control block diagram of a compressor frequency and an electric expansion valve opening degree in the embodiment.

FIG. 9 is a relationship diagram between a compressor frequency and a valve opening of a main electric expansion valve in the embodiment.

FIG. 10 is a refrigeration cycle diagram in a fifth embodiment of the multi-chamber air conditioning system of the present invention.

FIG. 11 is a control block diagram of a compressor frequency and an electric expansion valve opening degree in the embodiment.

FIG. 12 is a diagram showing a relationship between a compressor frequency and a target discharge temperature in the embodiment.

FIG. 13 is a relationship diagram between a difference ΔTdis between a target discharge temperature and a discharge temperature and an opening change amount of a main electric expansion valve.

FIG. 14 is a refrigeration cycle diagram of a conventional multi-chamber air conditioning system.

FIG. 15 is a diagram showing the relationship between the capacity ratio of the indoor and outdoor units of the system and the valve opening of the electric flow control valve.

[Explanation of symbols]

 Reference Signs List 1 outdoor unit 2a indoor unit 2b indoor unit 2c indoor unit 3 variable capacity (frequency) compressor 4 outdoor heat exchanger 5 four-way valve 6a indoor heat exchanger 6b indoor heat exchanger 6c indoor heat exchanger 7 liquid side main pipe 8a liquid Side branch pipe 8b Liquid side branch pipe 8c Liquid side branch pipe 9 Gas side main pipe 10a Gas side branch pipe 10b Gas side branch pipe 10c Gas side branch pipe 11a Electric expansion valve 11b Electric expansion valve 11c Electric expansion valve 12 Receiver 13 Main electric expansion Valve 14 Suction pipe 15 Bypass circuit 16 Auxiliary throttle 17a Indoor temperature sensor 17b Indoor temperature sensor 17c Indoor temperature sensor 18a Operation setting circuit 18b Operation setting circuit 18c Operation setting circuit 19 Suction temperature sensor 20 Saturation temperature sensor 21 Indoor temperature detection circuit 22 Differential temperature Calculation circuit 23 Setting discrimination circuit 24 ON-OFF discrimination circuit 25 Rated capacity storage circuit 6 Signal sending circuit 27 Signal receiving circuit 28 Compressor frequency calculating circuit 29 Expansion valve opening calculating circuit 30 Load constant table 31 Valve initial opening table 32 Suction temperature detecting circuit 33 Superheat degree calculating circuit 34 Saturation temperature detecting circuit 35 Valve initial opening Degree table 36 Discharge pipe 37 Discharge temperature sensor 38 Discharge temperature calculation circuit 39 Discharge temperature detection circuit 40 Discharge temperature difference calculation circuit

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masahiro Fujikawa 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-61-24937 (JP, A) JP-A-1-193563 (JP, A)

Claims (10)

(57) [Claims] 1. An outdoor unit having a variable capacity (frequency) variable compressor, a four-way valve, an outdoor heat exchanger, a main motor-operated expansion valve which can be electrically controlled, and a plurality of units having an indoor heat exchanger. A liquid-side branch pipe provided in the outdoor unit and branching a liquid-side main pipe through which refrigerant liquid mainly flows, and a gas side provided in the outdoor unit and branching a gas-side main pipe through which refrigerant gas mainly flows. A refrigeration cycle is configured by connecting via a branch pipe and interposing an electric expansion valve capable of electrically controlling the valve opening degree in each of the liquid side branch pipes, and setting a desired one in each of the indoor units. An indoor temperature setting means capable of setting an indoor temperature and an indoor temperature detecting means for detecting an indoor temperature are provided, and a difference between the set indoor temperature and the indoor temperature is calculated from the indoor temperature setting means and the indoor temperature detecting means. Temperature calculating means, and furthermore, each of the indoor units has a rated capacity. And an on / off determining unit for determining whether the indoor unit is operating or stopped for each of the indoor units, dividing a temperature range in which the temperature difference can be taken into a plurality of temperature zones, And a load constant storage means for determining and storing a load constant corresponding to an indoor load for each rated capacity of the indoor unit, and a valve initial opening storage means for determining and storing a valve initial opening for each rated capacity of the indoor unit. A compressor capacity is calculated at predetermined intervals using data obtained from the differential temperature calculating means, the capacity determining means, the on / off determining means, and the load constant storing means, and the capacity is calculated based on the calculation result. (Frequency) Compressor capacity control means for controlling the capacity of the variable compressor is provided, and when a plurality of the indoor units are operating, the data and the data obtained from the valve initial opening storage means are used. Valve opening degree control means for calculating the valve opening degree of each electric expansion valve connected to the operating indoor unit at predetermined intervals, and controlling the valve opening degree of the electric expansion valve based on the calculation result. Multi-room air conditioning system. 2. For each of the operating indoor units, a rated capacity and a load constant corresponding to the present differential temperature and a predetermined value of the load constant are read out from the load constant storage means, and the rated capacity is read from the valve initial opening degree storage means. Read the corresponding valve initial opening,
A request for calculating a product of a reciprocal of a predetermined value of a load constant, a load constant, and a valve initial opening for each indoor unit, and controlling the valve opening of the electric expansion valve connected to each indoor unit to be the product. Item 4. The multi-room air conditioning system according to Item 1. 3. An outdoor unit having a variable capacity (frequency) compressor, a four-way valve, an outdoor heat exchanger, a main motor-operated expansion valve which can be electrically controlled, and a plurality of units having an indoor heat exchanger. A liquid-side branch pipe provided in the outdoor unit and branching a liquid-side main pipe through which refrigerant liquid mainly flows, and a gas side provided in the outdoor unit and branching a gas-side main pipe through which refrigerant gas mainly flows. A refrigeration cycle is configured by connecting via a branch pipe and interposing an electric expansion valve capable of electrically controlling the valve opening degree in each of the liquid side branch pipes, and setting a desired one in each of the indoor units. An indoor temperature setting means capable of setting an indoor temperature and an indoor temperature detecting means for detecting an indoor temperature are provided, and a difference between the set indoor temperature and the indoor temperature is calculated from the indoor temperature setting means and the indoor temperature detecting means. Temperature calculating means, and furthermore, each of the indoor units has a rated capacity. And an on / off determining unit for determining whether the indoor unit is operating or stopped for each of the indoor units, dividing a temperature range in which the temperature difference can be taken into a plurality of temperature zones, And a load constant storage means for determining and storing a load constant corresponding to the indoor load for each rated capacity of the indoor unit, wherein the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means Compressor capacity control means for calculating the compressor capacity at predetermined intervals using the obtained data and controlling the capacity of the variable capacity (frequency) compressor based on the calculation result is provided. A valve initial opening storage means for determining and storing a valve initial opening for each electric expansion valve connected to each indoor unit for each combination of the number and the rated capacity is provided, and when a plurality of the indoor units are in operation, Is before Using the data and the data of the valve initial opening obtained from the valve initial opening storage means, the valve opening of each electric expansion valve connected to the operating indoor unit is calculated every predetermined cycle, and the calculation result is A multi-chamber air conditioning system provided with a valve opening control means for controlling a valve opening of the electric expansion valve based on the control. 4. For each of the operating indoor units, a rated capacity and a load constant corresponding to the present differential temperature and a predetermined value of the load constant are read from the load constant storage means, and the operating constant is read from the valve initial opening storage means. Read the valve initial opening corresponding to the combination of the number of indoor units and the rated capacity, calculate the product of the reciprocal of the predetermined value of the load constant, the load constant and the valve initial opening for each indoor unit,
The multi-room air conditioning system according to claim 3, wherein the valve opening of the electric expansion valve connected to each indoor unit is controlled so as to be the product. 5. An outdoor unit having a variable capacity (frequency) compressor, a four-way valve, an outdoor heat exchanger, a main motor-operated expansion valve which can be electrically controlled, and a plurality of units having an indoor heat exchanger. A liquid-side branch pipe provided in the outdoor unit and branching a liquid-side main pipe through which refrigerant liquid mainly flows, and a gas side provided in the outdoor unit and branching a gas-side main pipe through which refrigerant gas mainly flows. A refrigeration cycle is configured by connecting via a branch pipe and interposing an electric expansion valve capable of electrically controlling the valve opening degree in each of the liquid side branch pipes, and setting a desired one in each of the indoor units. An indoor temperature setting means capable of setting an indoor temperature and an indoor temperature detecting means for detecting an indoor temperature are provided, and a difference between the set indoor temperature and the indoor temperature is calculated from the indoor temperature setting means and the indoor temperature detecting means. Temperature calculating means, and furthermore, each of the indoor units has a rated capacity. And an on / off determining means for determining whether the indoor unit is operating or stopped for each of the indoor units, dividing a temperature range in which the temperature difference can be taken into a plurality of temperature zones, and And a load constant storage means for determining and storing a load constant corresponding to the indoor load for each rated capacity of the indoor unit, wherein the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means Compressor capacity is calculated at predetermined intervals using the obtained data, and compressor capacity control means for controlling the capacity of the capacity (frequency) variable compressor based on the calculation result is provided. A valve initial opening calculating means for calculating a valve initial opening for each electric expansion valve connected to each indoor unit by an approximate expression is provided, and when a plurality of the indoor units are operating, the data and First The valve opening of each motor-operated expansion valve connected to the operating indoor unit is calculated at predetermined intervals using data on the valve initial opening obtained by the valve opening calculating means, and the electric expansion is performed based on the calculation result. A multi-chamber air conditioning system provided with valve opening control means for controlling the valve opening of a valve. 6. For each of the operating indoor units, a rated capacity and a load constant corresponding to the current differential temperature and a predetermined value of the load constant are read out from the load constant storage means, and the valve initial opening degree calculating means reads out the operating constants. Calculate the valve initial opening using the data of the number of indoor units and the rated capacity, calculate the product of the reciprocal of the predetermined value of the load constant, the load constant and the valve initial opening for each indoor unit, and connect to each indoor unit The multi-room air conditioning system according to claim 5, wherein the controlled valve opening degree of the electric expansion valve is controlled to be equal to the product. 7. For each of the operating indoor units, a rated constant and a load constant corresponding to the current differential temperature and a predetermined value of the load constant are read from the load constant storage means, and the load constant and the load constant are read by the valve initial opening calculating means. Using the data of the number of indoor units in operation and the rated capacity, the valve initial opening is calculated, and the product of the reciprocal of a predetermined value of the load constant, the load constant, and the valve initial opening for each indoor unit is calculated. The multi-room air conditioning system according to claim 5, wherein the valve opening of the electric expansion valve connected to the air conditioner is controlled so as to be the product. 8. An electric expansion connected to an outdoor heat exchanger and a liquid-side branch pipe, provided with superheat degree detection means for detecting the degree of superheat of the refrigerant sucked into the variable capacity (frequency) compressor at predetermined intervals. Valve opening degree determining means for determining the valve opening degree of the main motor-operated expansion valve connected between the valves in accordance with the superheat degree data detected by the superheat degree detecting means is provided, and the valve opening degree control means The multi-room air conditioning system according to claim 1, wherein the valve opening is controlled. 9. The valve opening of the main electric expansion valve connected between the outdoor heat exchanger and the electric expansion valve connected to the liquid side branch pipe corresponds to the compressor capacity calculated by the compressor capacity control means. The multi-chamber air conditioning system according to any one of claims 1 to 7, further comprising a valve opening degree determining means for determining the valve opening degree, wherein the valve opening degree controlling means controls the valve opening degree. 10. A discharge temperature detecting means for detecting a temperature of a refrigerant discharged from a variable capacity (frequency) compressor at predetermined intervals, and a discharge temperature corresponding to a compressor capacity calculated by a compressor capacity control means. The compressor discharge temperature determining means is provided for determining the opening degree of the main electric expansion valve connected between the outdoor heat exchanger and the electric expansion valve connected to the liquid side branch pipe. The multi-chamber according to any one of claims 1 to 7, further comprising a valve opening determining means for determining the opening degree in accordance with the data of the detected discharge temperature, wherein the valve opening controlling means controls the valve opening. Type air conditioning system.