JPH06257827A - Multi chamber type air conditioning system - Google Patents

Abstract

PURPOSE:To provide a multi-chamber type air conditioning system for improving a comfortable feeling and making an energy saving by a method wherein its capability is realized in response to a requested capability of each of a plurality of chambers. CONSTITUTION:There are provided a temperature difference calculation circuit 22, a rated capacity memory circuit 25, an ON-OFF discriminating circuit 24, and a compressor capacity control means for calculating a compressor capacity for every period and controlling a capacity of a capacity variable (frequency) type compressor in response to a result of calculation by applying data got from a load constant table 30. During operation of a plurality of indoor devices 2a, 2b and 2c, a degree of opening of each of various electrical expansion valves connected to an indoor device being operated for every predetermined period by applying data and other data got by a valve initial opening degree table 31 for every rated capacity is calculated. There is provided a valve opening degree control means for controlling a valve opening degree of each of electrical expansion valves in response to the result of calculation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-chamber type 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 conditioning system in which a plurality of indoor units are connected to one outdoor unit has been accepted by ordinary household consumers in terms of space saving and aesthetics. is there.

Conventionally, in this multi-room type air conditioning system, a variable capacity (frequency) type compressor is used, and a refrigerant circulation amount control device for controlling the refrigerant circulation amount to each indoor unit in a liquid side refrigerant pipe of a refrigeration cycle. It has been proposed to control the compressor capacity and the refrigerant circulation amount to each indoor unit by comparing the capacity of the outdoor unit with the capacity of each indoor unit.
-294462).

The conventional multi-room air conditioning system will be described below with reference to the drawings. FIG. 15 is a refrigeration cycle diagram of a conventional multi-room air conditioning system.

This multi-room air conditioning system is constructed by connecting a plurality of outdoor units 50 via a branch unit 51, and two indoor units 52a and 52b in this conventional example. The outdoor unit 50 is equipped with a compressor 54 whose capacity is controlled by an inverter 53. The refrigeration cycle extends into the branch unit 51 through the compressor 54, the four-way valve 55, the outdoor heat exchanger 56, the heating expansion mechanism 57, and the receiver 58, which are incorporated in the outdoor unit 50, in the branch unit 51. The liquid-side refrigerant pipe 59 is branched according to the number of indoor units 52a and 52b. The branched liquid side refrigerant pipes 60a and 60b are provided with a refrigerant circulation amount control device 61 and a cooling expansion mechanism 62, respectively, and the refrigerant pipes 60a and 60b are connected to the indoor heat exchangers 63a and 63b of the indoor units 52a and 52b. Connected. The gas side refrigerant pipes 64a, 64b from the indoor heat exchangers 63a, 63b are provided with solenoid valves 65a, 65b as opening / closing valves in the branch unit 51, and then join the refrigerant pipes 66. The refrigerant pipe 66 is connected to the compressor 54 via the four-way valve 55. The heating and cooling expansion mechanisms 57 and 62 are composed of expansion valves 67 and 68, and an expansion valve bypass circuit is provided so as to bypass the expansion valves 67 and 68, respectively, and the check valve 6 is provided in this bypass circuit.
9, 70 are provided. On the other hand, the refrigerant circulation amount control device 61 provided in the branch unit 51 has an electric flow rate adjusting valve 71 provided in the liquid side refrigerant branch pipes 60a and 60b.
a, 71b, and these electric flow rate adjusting valves 71a, 71b
The valve opening of each indoor unit 52a, 52b is set according to the ratio between the capacity of the corresponding indoor unit 52a, 52b and the capacity of the outdoor unit 50, whereby each indoor unit 52a,
The flow rate of the refrigerant flowing through 52b is controlled.

In this multi-room 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 to the outdoor heat exchanger 56 via the four-way valve 55, After being condensed here, it is adiabatically expanded by the expansion valve 68 via the electric flow rate control valves 71a and 71b, flows to the indoor heat exchangers 63a and 63b, cools and evaporates the room there, 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 via the check valve 70, the electric flow rate adjusting valves 71a and 71b, flows to the outdoor heat exchanger 56 and evaporates there, and then passes through the four-way valve 55 and the compressor 54. Inhaled into.

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

[0009]

[Equation 1]

At this time, the electric flow rate adjusting valves 71a, 71b
15, the valve opening degrees are set to 50% and 72%, respectively. The compressor is turned on only from the indoor unit 52a.
When the signal is output, the required inverter output frequency P _f is represented by the following mathematical formula.

[0011]

[Equation 2]

At this time, the electric flow rate adjusting valves 71a, 71b
The valve opening of is set to 50% and 0%, respectively. In this way, in this multi-room air conditioning system, the compressor capacity corresponding to the capacity of the indoor unit and the valve opening degree of the electric flow rate adjusting valve are set and controlled, so that the refrigerant flow rate is changed even if the capacity of the indoor unit is changed. You can keep it optimal.

[0013]

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

That is, in the heating operation, for example, in each room in which the indoor unit is installed, the room temperature is quickly raised with a large capacity at the start of heating, and the capacity is gradually reduced as the room temperature approaches the set value, and the room temperature is set near the set value. It is necessary to keep it, but as an example, if two indoor units of 2 horsepower and 3 horsepower are installed, even if the required capacity of each room changes, only a constant capacity of 2 horsepower and 3 horsepower can be obtained. If the room temperature rises above the set value, the thermostat turns off and the electric flow control valve connected to the indoor unit is fully closed.When the room temperature drops below the set value, the thermostat turns on and the electric flow control valve is turned on. Repeated thermo-on and thermo-off such that the opening degree is set to a predetermined degree, the comfort level is reduced due to room temperature fluctuation, and the power consumption is increased. In addition, even if the compressor capacity is changed according to the total required capacity of each room as a solution to this problem, each capacity can be obtained only at a ratio of 2: 3.
For example, if the required capacity is 3: 2, 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 the thermostat is turned off.
After that, the thermo-on and the thermo-off were repeated, resulting in a decrease in comfort and an increase in power consumption.

In view of the above problems, the multi-room air conditioning system of the present invention does not complicate the structure of the refrigeration cycle,
It aims to improve comfort and save energy by exerting the ability according to the required capacity of each of the multiple rooms.

Further, another multi-room type air conditioning system of the present invention exerts the ability corresponding to the required capacity of each of the plurality of rooms while keeping the refrigeration cycle optimal, thereby improving comfort and saving energy. The purpose is to plan.

[0017]

In order to solve the above problems, the multi-room air conditioning system of the present invention has a capacity (frequency).
A liquid-side main pipe in which one outdoor unit having a variable compressor, a four-way valve, an outdoor heat exchanger, and a plurality of indoor units having an indoor heat exchanger are provided in the outdoor unit, and a refrigerant liquid mainly flows. A liquid side branch pipe that is branched and a gas side main pipe in which a refrigerant gas mainly flows provided in the outdoor unit is connected via a branched gas side branch pipe, and the valve opening is electrically connected to each of the liquid side branch pipes. A refrigeration cycle is configured by interposing an electric expansion valve capable of controlling the room temperature, 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. A temperature difference calculating means for calculating a temperature difference between the set room temperature and the room temperature from the room temperature setting means and the room temperature detecting means; and a capacity determining means for determining a rated capacity of each of the indoor units, Operate for each of the indoor units An on / off determination means for determining whether the temperature is stopped or not is provided, the temperature range that the differential temperature can take is divided into a plurality of temperature zones, and the indoor load is handled for each temperature zone and for each rated capacity of the indoor unit. A load constant storage means for defining and storing a load constant is provided, and a valve initial opening storage means for defining and storing a valve initial opening for each rated capacity of the indoor unit is provided,
The compressor capacity is calculated for each predetermined cycle using the data obtained from the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means, and the capacity (frequency) is calculated based on the calculation result. A compressor capacity control means for controlling the capacity of the variable compressor is provided, and when a plurality of the indoor units are in operation, a predetermined cycle is obtained using the data and the data obtained from the valve initial opening degree storage means. Calculate the valve opening of each electric expansion valve connected to the operating indoor unit for each
Valve opening control means for 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 is one outdoor unit having a variable capacity (frequency) compressor, a four-way valve, an outdoor heat exchanger, and a plurality of indoor heat exchangers. The indoor unit of the table, the liquid side branch pipe provided in the outdoor unit to branch the liquid side main pipe mainly flowing the refrigerant liquid, and the gas side provided in the outdoor unit to branch the gas side main pipe mainly flowing the refrigerant gas A refrigeration cycle is configured by connecting an electric expansion valve whose valve opening is electrically controllable to each of the liquid side branch pipes by connecting via a branch pipe, and forming a refrigeration cycle in each of the indoor units as desired. An indoor temperature setting means capable of setting the indoor temperature and an indoor temperature detecting means for detecting the indoor temperature are provided, and a difference for calculating a temperature difference between the set indoor temperature and the indoor temperature from the indoor temperature setting means and the indoor temperature detecting means. A temperature calculating means is provided, and each of the indoor units is further A capacity discriminating means for discriminating the rated capacity and an on / off discriminating means for discriminating whether each of the indoor units is in operation or not are provided, and the temperature range in which the differential temperature can be divided is divided into a plurality of temperature zones. A load constant storage means for determining and storing a load constant corresponding to an indoor load for each zone and for each rated capacity of the indoor unit is provided, and the differential temperature calculation means, the capacity determination means, the on / off determination means, the load constant storage Compressor capacity is calculated for each predetermined cycle using the data obtained from the means, and compressor capacity control means for controlling the capacity of the capacity (frequency) variable type compressor is provided on the basis of this calculation result. A valve initial opening degree storage means for determining and storing a valve initial opening degree for each electric expansion valve connected to each indoor unit for each combination of the number of indoor units and rated capacity is provided, and a plurality of the indoor units are in operation. In this case, the valve opening degree of each electric expansion valve connected to the operating indoor unit is calculated for each predetermined cycle using the above data and the data of the valve initial opening degree obtained from the valve initial opening degree storage means. A valve opening control means for controlling the valve opening of the electric expansion valve based on the calculation result is provided.

Further, another multi-room type air conditioning system of the present invention is one outdoor unit having a variable capacity (frequency) compressor, a four-way valve, an outdoor heat exchanger, and a plurality of indoor heat exchangers. The indoor unit of the table, the liquid side branch pipe provided in the outdoor unit to branch the liquid side main pipe mainly flowing the refrigerant liquid, and the gas side provided in the outdoor unit to branch the gas side main pipe mainly flowing the refrigerant gas A refrigeration cycle is configured by connecting an electric expansion valve whose valve opening is electrically controllable to each of the liquid side branch pipes by connecting via a branch pipe, and forming a refrigeration cycle in each of the indoor units as desired. An indoor temperature setting means capable of setting the indoor temperature and an indoor temperature detecting means for detecting the indoor temperature are provided, and a difference for calculating a temperature difference between the set indoor temperature and the indoor temperature from the indoor temperature setting means and the indoor temperature detecting means. A temperature calculating means is provided, and each of the indoor units is further A capacity discriminating means for discriminating the rated capacity and an on / off discriminating means for discriminating whether each of the indoor units is in operation or not are provided, and the temperature range in which the differential temperature can be divided is divided into a plurality of temperature zones. A load constant storage means for determining and storing a load constant corresponding to an indoor load for each zone and for each rated capacity of the indoor unit is provided, and the differential temperature calculation means, the capacity determination means, the on / off determination means, the load constant storage Compressor capacity is calculated for each predetermined period using the data obtained from the means, and compressor capacity control means for controlling the capacity of the capacity (frequency) variable type compressor is provided based on the calculation result. Provided with a valve initial opening degree calculating means for calculating the valve initial opening degree of each electric expansion valve connected to each indoor unit by an approximate expression using the above-mentioned data when a plurality of the indoor units are in operation. Oh And the valve opening degree of each electric expansion valve connected to the operating indoor unit is calculated for each predetermined cycle using the data of the valve opening degree obtained from the valve opening degree calculation means, and based on this calculation result Valve opening control means for controlling the valve opening of the electric expansion valve.

Further, another multi-chamber type air conditioning system of the present invention is provided with superheat detecting means for detecting the superheat of the refrigerant sucked into the variable displacement (frequency) compressor at predetermined intervals.
A valve opening change amount determining means for determining the change amount of the valve opening degree of the electric expansion valve connected to the operating indoor unit in correspondence with the superheat degree data detected by the superheat degree detecting means is provided. The opening control means controls the valve opening.

Further, another multi-chamber type air conditioning system of the present invention is provided with superheat detecting means for detecting the superheat of the refrigerant sucked into the variable displacement (frequency) compressor at predetermined intervals.
A valve opening change amount sum total determination means for determining the sum of the change amounts of the valve opening degree of the electric expansion valve connected to the indoor unit in operation corresponding to the superheat degree data detected by the superheat degree detecting means. The valve opening control means is provided to control the valve opening.

Further, in another multi-room type air conditioning system of the present invention, the sum of the valve opening degrees of the electric expansion valves connected to the operating indoor unit is set to the compressor capacity calculated by the compressor capacity control means. A valve opening total sum determining means for correspondingly determining is provided, and each valve opening degree is controlled by the valve opening control means.

In another multi-chamber air conditioning system of the present invention, discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the variable displacement (frequency) compressor at predetermined intervals, and the discharge temperature are compressed. Providing a compressor discharge temperature determining means for determining corresponding to the compressor capacity calculated by the machine capacity control means,
Provided is a valve opening change amount determination means for determining the amount of change in the valve opening degree of the electric expansion valve connected to the operating indoor unit, corresponding to the data of the discharge temperature detected by the discharge temperature detection means,
The valve opening control means controls the valve opening.

[0024]

The present invention operates as follows by the above means. That is, 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 temperature difference calculating means for calculating a temperature difference from the indoor temperature is provided, and a capacity determining means for determining a rated capacity of each indoor unit and an on / off determining means for determining whether each indoor unit is in operation or stopped. And a load constant storage means for dividing the temperature range of the differential temperature into a plurality of temperature zones, determining and storing a load constant corresponding to an indoor load for each temperature zone and for each rated capacity of the indoor unit. And a valve initial opening degree storage means for determining and storing a valve initial opening degree for each rated capacity of the indoor unit, the difference temperature calculation means, the capacity determination means, the on / off determination means, the negative Compressor capacity is calculated for each predetermined cycle using data obtained from the constant storage means, and compressor capacity control means for controlling the capacity of the variable capacity (frequency) compressor based on the calculation result is provided. When a plurality of indoor units are 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 obtained from the valve initial opening degree storage means. The valve opening control means for controlling the valve opening of the electric expansion valve based on the calculation result, thereby controlling the compressor frequency according to the total required capacity of each room, and Since the opening degree of each electric expansion valve is determined according to the load of each room, it is possible to distribute the necessary capacity to the necessary room, improve comfort and save energy.

Further, each indoor unit 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 the indoor temperature setting means and the indoor temperature detecting means are used for setting. A temperature difference calculating means for calculating the temperature difference between the indoor temperature and the indoor temperature is provided, and further capacity determining means for determining the rated capacity of each of the indoor units and determining whether each of the indoor units is operating or stopped. A load that is provided with an on / off determination means, divides the temperature range that the differential temperature can take into a plurality of temperature zones, and determines and stores a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant capacity storage means is provided, and the compressor capacity is calculated every predetermined cycle using data obtained from the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means. Then, compressor capacity control means for controlling the capacity of the capacity (frequency) variable compressor based on the calculation result is provided, and the compressor is connected to each indoor unit for each combination of the number of operating indoor units and the rated capacity. A valve initial opening degree storage means for determining and storing a valve initial opening degree for each electric expansion valve is provided, and when a plurality of indoor units are in operation, the data and the valve initial opening degree storage means are obtained. The valve opening degree of each electric expansion valve connected to the operating indoor unit is calculated every predetermined period using the data of the valve initial opening degree, and the valve opening degree of the electric expansion valve is controlled based on the calculation result. By providing a valve opening control means for controlling the compressor frequency according to the total required capacity of each room and determining the opening of each electric expansion valve according to the load of each room, it is necessary. Capacity can be distributed to the required room, and the valve can be opened initially. The Since determined for each combination of the number of operating units and its rated capacity of the indoor unit, it is capable of capacity control more finely accuracy can be improved and energy saving comfort.

Further, 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 the indoor temperature setting means and the indoor temperature detecting means set the indoor temperature. A temperature difference calculating means for calculating the temperature difference between the indoor temperature and the indoor temperature is provided, and further capacity determining means for determining the rated capacity of each of the indoor units and determining whether each of the indoor units is operating or stopped. A load that is provided with an on / off determination means, divides the temperature range that the differential temperature can take into a plurality of temperature zones, and determines and stores a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant capacity storage means is provided, and the compressor capacity is calculated every predetermined cycle using data obtained from the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means Then, compressor capacity control means for controlling the capacity of the capacity (frequency) variable compressor based on the calculation result is provided, and each electric expansion valve connected to each indoor unit by an approximate expression using the data. Is provided with a valve initial opening calculation means for calculating the valve initial opening, and when a plurality of the indoor units are in operation, the data and the data of the valve initial opening obtained from the valve initial opening calculation means. Valve opening control means for calculating the 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. Since the valve initial opening is calculated by an approximate expression for each combination of the number of operating indoor units and their rated capacities, it is possible to perform finer and more precise capacity control, improve comfort and save energy. Can be planned. Further, since the table of the valve initial opening is not required, it is not necessary to increase the capacity of the memory circuit even if the number of combinations of indoor units increases.

Further, a superheat degree detecting means for detecting the superheat degree of the refrigerant sucked into the variable capacity (frequency) type compressor at predetermined intervals is provided, and the electric expansion valve connected to the operating indoor unit is opened. By providing a valve opening change amount determining means for determining the change amount of the degree of heat in correspondence with the superheat data detected by the superheat detecting means, and controlling the valve opening by the valve opening control means. Since the control is performed so as to maintain the superheat degree of the refrigerant sucked into the compressor at a predetermined value, it is possible to improve comfort and save energy while controlling the refrigeration cycle more finely and optimally.

Further, a superheat degree detecting means for detecting the superheat degree of the refrigerant sucked into the variable capacity (frequency) type compressor at predetermined intervals is provided, and the electric expansion valve connected to the operating indoor unit is opened. Degree of valve opening change amount determining means for determining the total sum of the degree of change of temperature corresponding to the data of the degree of superheat detected by the degree of superheat detection means, and the valve opening degree control means controls the valve opening degree. By doing so, control is performed so as to maintain the superheat degree of the refrigerant sucked into the compressor at a predetermined value, so that it is possible to improve comfort and save energy while controlling the refrigeration cycle more finely and optimally.

Further, there is provided a total valve opening degree determining means for determining the total valve opening degree of the electric expansion valve connected to the operating indoor unit in accordance with the compressor capacity calculated by the compressor capacity control means. By controlling this valve opening with the valve opening control means, the valve opening of the electric expansion valve is determined according to the compressor frequency, so that the refrigeration cycle is kept optimal without complicating the configuration. However, it is possible to improve comfort and save energy.

Further, the discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the variable capacity (frequency) compressor at predetermined intervals and the discharge temperature corresponding to the compressor capacity calculated by the compressor capacity control means. A compressor discharge temperature determining means is provided to determine the valve opening change amount of the electric expansion valve connected to the operating indoor unit in accordance with the discharge temperature data detected by the discharge temperature detecting means. A valve opening change amount determining means is provided, and the valve opening control means controls the valve opening to control the compressor discharge temperature to a predetermined value, thus complicating the configuration. It is possible to improve comfort and save energy while controlling the refrigeration cycle more finely and optimally.

[0031]

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

In the figure, 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 heating and cooling, and indoors. Indoor heat exchangers 6a, 6b, 6c are provided in the machines 2a, 2b, 2c, respectively. The outdoor unit 1 and the indoor units 2a, 2b, 2c are divided into liquid side branch pipes 8a, 8 branched from a liquid side main pipe 7 provided in the outdoor unit 1.
b, 8c and gas side branch pipes 10a, 10b, 10c branched from the gas side main pipe 9 provided in the outdoor unit 1. The liquid side branch pipes 8a, 8b, 8c are respectively provided with electric expansion valves 11a, 11b, 11c whose pulse opening is controllable by using a stepping motor, and the liquid side main pipe 7 is provided with a refrigerant liquid. A receiver 12 capable of storing water is provided, and an auxiliary throttle 13 is provided to maintain the receiver 12 at an intermediate pressure for both cooling and heating. Further, a bypass circuit 15 that connects 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. In addition, each indoor unit 2a, 2b, 2c has an indoor temperature sensor 17a, 17b, 17c for detecting the room temperature of the room in which the indoor unit is installed, and an operation mode (cooling or heating) desired by the occupant and the room temperature. Operation setting circuits 18a, 18b, 18c capable of setting operation and stop are provided. Further, the suction pipe 14 is provided with a suction temperature sensor 19 for detecting the temperature of the refrigerant flowing through it, and the bypass circuit 15 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 be condensed and liquefied.
The pressure is reduced by the auxiliary throttle 13 to an intermediate pressure. Then, a part of the liquid refrigerant is stored in the receiver 12, and the rest is branched to the liquid side branch pipes 8a, 8b, 8c. Electric expansion valve 11a, 1
Since the valve openings of 1b and 11c are controlled by the control method described later so as to be the openings corresponding to the load of each room, the refrigerant also becomes a low pressure at a flow rate corresponding to each load, and indoor heat exchange is performed. After flowing to the vessels 6a, 6b, 6c and evaporating,
The gas side branch pipes 10a, 10b and 10c pass through the gas side main pipe 9 and the four-way valve 5 and are again sucked into the compressor 3. Further, 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 to be sucked into the suction pipe 14.
Flows to. At this time, the refrigerant that has passed through the auxiliary throttle 16 is a gas-liquid two-phase flow, and the pressure is almost the same as that of the refrigerant that flows through the suction pipe 14. Therefore, the saturation temperature can be detected by the saturation temperature sensor 20. Further, the compressor frequency is determined by a control method described later according to the total load.

The refrigerant discharged from the compressor 3 during heating is
Gas side branch pipe 10 from gas side main pipe 9 by switching four-way valve 5
a, 10b, 10c branch to indoor heat exchangers 6a, 6
b and 6c, condensed and liquefied, and liquid side branch pipes 8a and 8
The pressure is reduced by the electric expansion valves 11a, 11b, and 11c on b and 8c to an intermediate pressure. The electric expansion valve 11 includes 11b, 11
Since the valve opening degree of c is controlled to be an opening degree corresponding to the load of each room by the control method described later similarly to the case of cooling, the refrigerant also has a flow rate corresponding to each load in the indoor heat exchanger. It flows through 6a, 6b and 6c. As for the refrigerant having the intermediate pressure, a part of the liquid refrigerant is stored in the receiver 12, and the remaining refrigerant is decompressed by the auxiliary throttle 13 to become a low pressure and thus the outdoor heat exchanger 4
Flow through the four-way valve 5 to evaporate, and then pass through the four-way valve 5 again
Inhaled into. Further, it flows from the receiver 12 to a very small amount of the liquid refrigerant bypass circuit 15, is decompressed by the auxiliary throttle 16, and then flows into the suction pipe 14. As in the case of cooling, the refrigerant passing through the auxiliary throttle 16 is a gas-liquid two-phase flow, and the pressure is almost equal to that of the refrigerant flowing in the suction pipe 14, so the saturation temperature sensor 2
The saturation temperature can be detected at 0. 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.

FIG. 2 is a block diagram showing the flow of control of the compressor frequency and the electric expansion valve opening, FIG. 3 is a temperature zone division diagram of the temperature difference ΔT between the room temperature T _r and the set temperature T _s, and FIG. 4 is overheating. It is a relationship diagram between the degree SH and the opening change amount of the 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 differential temperature calculating circuit 22 as a temperature signal, and the setting determining circuit 23 is also provided.
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 to calculate the temperature difference ΔT (= T _r −T _s ), and the load shown in FIG. The number Ln value is converted and used as a temperature difference signal. For example, if T _r = 27.3 ° C. and T _s = 26 ° C. during cooling operation, Ln = 6 at a temperature difference ΔT = 1.3 ° C. Also ON-
The OFF discrimination circuit 24 discriminates the operation (ON) or stop (OFF) of the indoor unit 2a set by the operation setting circuit 18a, and further stores the rated capacity of the indoor unit 2a in the rated capacity storage circuit 25. The rated capacity signal, the differential temperature signal, the operation mode signal, and the ON-OFF determination signal are sent from the signal sending circuit 26 to the signal receiving circuit 27 of the outdoor unit 1. Similar signals are sent to the signal receiving circuit 27 from the indoor units 2b and 2c. The signal received by the signal receiving circuit 27 is sent to the compressor frequency calculating circuit 28 and the expansion valve opening calculating circuit 29.
However, if different operation mode signals exist, the operation mode of the indoor unit that started operation first is given priority, and the indoor units in different operation modes are considered to be stopped and turned on.
The OFF determination signal always outputs OFF.

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

[0038]

[Table 1]

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

[0040]

[Table 2]

From Tables 1 and 2, the indoor units 2a, 2b, 2c
Load constants of 1.5, 1.0 and 1.9 respectively,
Therefore, the frequency Hz of the compressor 3 becomes Hz = A × (1.5 + 1.0 + 1.9) = A × 4.4 when A is a constant, and the calculation result is used as a frequency signal in a compressor drive circuit (not shown). ) To control the frequency of the compressor 3. Thereafter, the rated capacity signal of each of the indoor units 2a, 2b, 2c, the temperature difference signal, the operation mode signal, O
Calculation is performed from the N-OFF discrimination 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 rated capacity signals of the indoor units 2a, 2b, 2c,
Select a load constant from the load constant table 30 shown in Table 1 from the differential temperature signal, the operation mode signal, and the ON-OFF discrimination signal,
Furthermore, from the rated capacity of each of the indoor units 2a, 2b, 2c, a valve initial opening table 31 for each rated capacity shown in Table 3 below.
Read from. The initial valve opening is determined so that each indoor unit can perform a predetermined capacity control even when different indoor units having different rated capacities are combined.

[0043]

[Table 3]

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

The (load constant / predetermined load constant) of the indoor units 2a, 2b, 2c is (1.5 / 2.0) and (1.0), respectively.
/2.5), (1.9 / 3.2), and the valve initial opening degrees are 100, 130, and 180, respectively. Therefore, the valve opening degree of the electric expansion valves 11a, 11b, 11c is 7
5,52,107 (rounded to one decimal place). The result of this calculation is sent to an expansion valve drive circuit (not shown) as an expansion valve opening signal. Therefore, the valve opening degrees of the electric expansion valves 11a, 11b, and 11c are 75 pulses, 52 pulses, and 107 pulses, respectively, and thereafter, the electric expansion valve is calculated from the differential temperature signal, the operation mode signal, and the ON-OFF determination signal at predetermined intervals. The valve opening degrees of 11a, 11b, and 11c are calculated, and the results of these calculations are sent to an expansion valve drive circuit (not shown) as an expansion valve opening signal. Further, the output of the intake temperature sensor 19 is sent from the intake temperature detecting circuit 32 to the superheat degree calculating circuit 33 as a temperature signal, and the output of the saturation temperature sensor 20 is sent from the saturation temperature detecting circuit 34 to the superheat degree calculating circuit 33 as a temperature signal. Then, the superheat degree SH (= intake temperature−saturation temperature) is calculated here and sent to the expansion valve opening degree calculation circuit 29. The expansion valve opening calculation circuit 29 calculates the valve opening change pulse number as shown in FIG. 4 according to the sent superheat degree SH, and drives the electric expansion valves 11a, 11b, 11c (not shown). Control).

Although the above description was mainly made for cooling, the same control can be made for heating. In this way, the compressor frequency is controlled according to the total required capacity of each room, and the opening degree of each electric expansion valve is determined according to the load of each room. At the same time, the control is performed so that the superheat degree of the refrigerant sucked into the compressor is maintained at a predetermined value. Therefore, it is possible to improve comfort and save energy while finely and optimally controlling the refrigeration cycle.

Next, a 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 degree in the second embodiment of the present invention. The drawing is different from FIG. 2 which is a block diagram of the first embodiment in that the number of operating indoor units and their rated capacities are replaced by the valve initial opening table 31 determined corresponding to the rated capacity of the indoor units. That is, the valve initial opening degree table 35 determined for each combination is used. This valve initial opening degree table 35 is represented as shown in Table 4 below.

[0048]

[Table 4]

The electric expansion valves 11a, 11b, 11
The valve opening degree of c is obtained by dividing each load constant by a predetermined value of the load constant and multiplying the valve initial opening degree. In this way, since the initial valve opening is determined for each combination of the number of operating indoor units and their rated capacities, it is possible to perform finer and more precise capacity control, improve comfort and save energy. .

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 degree in the third embodiment of the present invention. The drawing is different 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 degree is calculated by the expansion valve opening degree calculation circuit 29 from the operating number of indoor units and their rated capacities by an approximate expression.

For example, the initial valve opening degree of the indoor unit 2a is represented by f (rated capacity of the indoor unit 2a, number of operating units, and rated capacity of other operating indoor units) (f indicates a function). The same applies to the indoor units 2b and 2c. The valve opening degree of each 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 valve initial opening degree.

As described above, since the valve initial opening is calculated by an approximate expression for each combination of the number of operating indoor units and their rated capacities, it is possible to perform finer and more precise performance control, and to improve comfort. It is possible to save energy. Also, since a table of valve initial opening is not required,
Further, even if the number of combinations of indoor units increases, it is not necessary to increase the capacity of the memory circuit. In the above embodiment, the initial valve opening degree of the indoor unit 2a is represented by f (rated capacity of the indoor unit 2a, number of operating units, and other rated capacity of the operating indoor unit). 2a rated capacity, indoor unit 2a load constant, number of operating units, and other rated indoor unit capacity)
The accuracy can be further improved by creating the approximate expression as (the same applies to the indoor units 2b and 2c).

Next, a fourth embodiment of the present invention will be described with reference to the drawings. The refrigeration cycle in the fourth embodiment is the same as that in the first embodiment shown in FIG. 1, and is a block showing the flow of control of the compressor frequency and the electric expansion valve opening degree in the fourth embodiment. The figure is the same as FIG. FIG. 7 is a relationship diagram between the degree of superheat SH and the sum of the valve opening change amounts of the electric expansion valve.

The present embodiment differs from the first to third embodiments in that the output of the intake temperature sensor 19 is sent from the intake temperature detection circuit 32 to the superheat degree calculation circuit 33 as a temperature signal,
The output of the saturation temperature sensor 20 is sent from the saturation temperature detection circuit 34 as a temperature signal to the superheat degree calculation circuit 33, where the superheat degree SH (= intake temperature-saturation temperature) is calculated and is sent to the expansion valve opening degree calculation circuit 29. The total number of valve opening change pulses is calculated as shown in FIG. 7 according to the sent superheat degree SH, and each expansion valve is calculated according to the valve opening ratio of the electric expansion valves 11a, 11b, 11c. Calculate the opening and drive circuit (not shown)
It is a point to send out to and control.

A method of controlling the compressor frequency and the electric expansion valve opening degree in the present embodiment will be described. In FIG. 5, the compressor frequency calculation circuit 28 in the indoor units 2a, 2b ,.
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 determination signal of 2c, and the compressor 3 is obtained by multiplying the total of the load constants by the constant. Up to the point of determining the frequency, the same as in the first to fourth embodiments. 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 also sent to the expansion valve opening calculation circuit 29. After that, the calculation is performed from the rated capacity signal, the temperature difference signal, the operation mode signal, and the ON-OFF determination signal of each of the indoor units 2a, 2b, 2c at predetermined intervals, and the calculation result is used as a frequency signal in the compressor drive circuit (see (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 indoor unit 2
a, 2b, 2c rated capacity signal, differential temperature signal,
A load constant is selected from the load constant table 30 shown in Table 1 from the operation mode signal and the ON-OFF discrimination signal, and the valve initial opening for each rated capacity shown in Table 3 from the rated capacity of each indoor unit 2a, 2b, 2c. The valve initial opening is read from the table 31. The valve opening degrees of the electric expansion valves 11a, 11b, 11c are obtained by dividing each load constant by a predetermined value of the load constant and multiplying the valve initial opening degree.

Here, as in the case of the first embodiment, the case where the signals from the indoor units 2a, 2b, 2c are shown in Table 2 will be specifically described. The (load constant / predetermined load constant) of the indoor units 2a, 2b, 2c is (1.5 / 2.0),
(1.0 / 2.5) and (1.9 / 3.2), and the valve initial openings are 100, 130 and 180, respectively.
Therefore, the valve opening degrees of the electric expansion valves 11a, 11b, 11c are 75, 52, 107 (rounded to the first decimal place). In addition, the superheat calculation circuit 33 outputs the output of the intake temperature sensor 19 as a temperature signal from the intake temperature detection circuit 32.
And outputs the output of the saturation temperature sensor 20 from the saturation temperature detection circuit 34 to the superheat degree calculation circuit 33 as a temperature signal, where the superheat degree SH (= intake temperature-saturation temperature) is calculated and the expansion valve opening degree is calculated. According to the superheat degree SH sent to the arithmetic circuit 29, the total number of valve opening change pulses is calculated as shown in FIG. 7, and the electric expansion valves 11a, 11b, 11c are calculated.
Each expansion valve opening is calculated based on the ratio of the valve opening of the above, and is sent to a drive circuit (not shown).

In this way, the required frequency is required because the compressor frequency is controlled according to the total required capacity of each room and the opening degree of each electric expansion valve is determined according to the load of each room. It can be distributed to various rooms, and at the same time, control is performed so that the superheat degree of the refrigerant sucked into the compressor is maintained at a predetermined value. Therefore, it is possible to improve comfort and save energy while finely and optimally controlling the refrigeration cycle.

Next, a fifth embodiment will be described. Figure 8
[Fig. 8] is a refrigeration cycle diagram in a fifth embodiment of the multi-room air conditioning system of the present invention. This refrigeration cycle is different from the first to fourth embodiments in that there is no circuit or sensor for detecting the degree of superheat of the refrigerant flowing through the suction pipe 14. That is, the refrigeration cycle of FIG. 8 does not include the bypass circuit 15, the saturation temperature sensor 20, and the suction temperature sensor 19 of the refrigeration cycle of FIG. Further, FIG. 9 is a block diagram showing a flow of control of the compressor frequency and the electric expansion valve opening degree of the present embodiment, and FIG. 10 is a relationship diagram between the compressor frequency and the total valve opening degree of the electric expansion valve.

A method of controlling the compressor frequency and the electric expansion valve opening degree in the present embodiment will be described. In FIG. 9, the compressor frequency calculation circuit 28 is used to control the indoor units 2a, 2b ,.
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 determination signal of 2c, and the compressor 3 is obtained by multiplying the total of the load constants by the constant. Up to the point of determining the frequency, the same as in the first to fourth embodiments. 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 also sent to the expansion valve opening calculation circuit 29. After that, the calculation is performed from the rated capacity signal, the temperature difference signal, the operation mode signal, and the ON-OFF determination signal of each of the indoor units 2a, 2b, 2c at predetermined intervals, and the calculation result is used as a frequency signal in the 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 indoor unit 2
a, 2b, 2c rated capacity signal, differential temperature signal,
A load constant is selected from the load constant table 30 shown in Table 1 from the operation mode signal and the ON-OFF discrimination signal, and the valve initial opening for each rated capacity shown in Table 3 from the rated capacity of each indoor unit 2a, 2b, 2c. The valve initial opening is read from the table 31. The valve opening degrees of the electric expansion valves 11a, 11b, 11c are obtained by dividing each load constant by a predetermined value of the load constant and multiplying the valve initial opening degree.

Here, as in the case of the first embodiment, the case where the signals from the indoor units 2a, 2b, 2c are shown in Table 2 will be specifically described. The (load constant / predetermined load constant) of the indoor units 2a, 2b, 2c is (1.5 / 2.0),
(1.0 / 2.5) and (1.9 / 3.2), and the valve initial openings are 100, 130 and 180, respectively.
Therefore, the valve opening degrees of the electric expansion valves 11a, 11b, 11c are 75, 52, 107 (rounded to the first decimal place). Further, the total valve opening of the electric expansion valves 11a, 11b, 11c is calculated from the frequency sent from the compressor frequency calculation circuit 28 using the relationship shown in FIG.

Considering the case where the frequency sent from the compressor frequency arithmetic circuit 28 is 75 Hz, the total valve opening of the electric expansion valves 11a, 11b, 11c is 700 pulses from FIG. Then, according to the above-mentioned valve opening ratio, each valve opening is 224 pulses for the electric expansion valve 11a and 15 for 11b.
Six pulses and 11c become 320 pulses, and the calculation result is sent to an expansion valve drive circuit (not shown) as an expansion valve opening signal. After that, the compressor frequency calculation circuit 2 is executed every predetermined period.
The total valve opening is changed in accordance with the frequency signal sent from 8 and the electric expansion is performed from the rated capacity signal of each indoor unit 2a, 2b, 2c, the temperature difference signal, the operation mode signal, and the ON-OFF discrimination signal. The valve opening degrees of the valves 11a, 11b, 11c are calculated, and the calculation result is sent to an expansion valve drive circuit (not shown) as an expansion valve opening signal.

In this way, the required frequency is required in order to control the compressor frequency according to the total required capacity of each room and to determine the opening degree of each electric expansion valve according to the load of each room. It can be distributed to different rooms, and at the same time, the valve opening of the electric expansion valve is determined according to the compressor frequency. It is possible to save energy.

Next, a sixth embodiment will be described. Figure 1
FIG. 1 is a refrigeration cycle diagram in a sixth embodiment of the multi-room air conditioning system of the present invention. The difference between this refrigeration cycle and the first to fifth embodiments is that a discharge temperature sensor 37 for detecting the temperature of the refrigerant flowing through the discharge pipe 36.
Is provided. Further, FIG. 12 is a block diagram showing the flow of control of the compressor frequency and the electric expansion valve opening degree of the present embodiment, and FIG. 13 is a relationship diagram between the compressor frequency and the valve opening degree of the main electric expansion valve.

A method of controlling the compressor frequency and the electric expansion valve opening degree in this embodiment will be described. In FIG. 11, the compressor frequency calculation circuit 28 is used to control the indoor units 2a and 2a.
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 of each of b and 2c, and the sum of the load constants is multiplied by the constant to be compressed. Up to the point of determining the frequency of the machine 3, it is the same as in the first to fifth embodiments. 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 also sent to the discharge temperature calculation circuit 38. After that, the calculation is performed from the rated capacity signal, the temperature difference signal, the operation mode signal, and the ON-OFF determination signal of each of the indoor units 2a, 2b, 2c at predetermined intervals, and the calculation result is used as a frequency signal in the 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 calculation circuit 29, the load constant table 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 indoor unit 2a, 2b, 2c. A load constant is selected from 30, and a valve initial opening table 31 for each rated capacity shown in Table 3 based on the rated capacity of each indoor unit 2a, 2b, 2c.
Read the valve initial opening from. Electric expansion valve 11a, 11
The valve opening degrees of b and 11c are obtained by dividing each load constant by a predetermined value of the load constant and multiplying the valve initial opening degree. Further, the discharge temperature calculation circuit 38 calculates a target discharge temperature corresponding to the frequency signal sent from the compressor frequency calculation circuit 28, and the discharge temperature difference calculation circuit 40 as a temperature signal.
And the output of the discharge temperature sensor 37 as a temperature signal from the discharge temperature detection circuit 39.
0, the discharge temperature difference (= discharge temperature-target discharge temperature temperature) ΔTdis is calculated here, and the expansion valve opening degree calculation circuit 2
9 is sent. The expansion valve opening calculation circuit 29 calculates the valve opening change pulse number as shown in FIG. 14 according to the delivered discharge temperature difference ΔTdis, and the electric expansion valves 11 a, 1
It is sent to a drive circuit (not shown) of 1b and 11c and controlled.

As described above, the required frequency is required because the compressor frequency is controlled according to the total required capacity of each room and the opening degree of each electric expansion valve is determined according to the load of each room. It can be distributed to different rooms, and at the same time, the compressor discharge temperature is controlled so as to keep it at a predetermined value, so that the refrigeration cycle is kept more optimal and comfort is improved and energy is saved without complicating the configuration. be able to.

[0067]

As is apparent from the above embodiment, the multi-room air conditioning system of the present invention has a room temperature setting means capable of setting a desired room temperature and a room temperature detecting the room temperature for each indoor unit. A detection means is provided, and a temperature difference calculation means for calculating a temperature difference between the set room temperature and the room temperature is provided from the room temperature setting means and the room temperature detection means, and the rated capacity of each of the indoor units is determined. A capacity determining means and an on / off determining means for determining whether each of the indoor units is in operation or stopped are provided, and the temperature range in which the differential temperature can be taken is divided into a plurality of temperature zones, and each temperature zone and an indoor unit 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 is provided, and a valve initial opening degree storage means for determining and storing the valve initial opening degree for each rated capacity of the indoor unit is provided, Previous Differential temperature calculating means, the capacitance determining means,
Using the data obtained from the on / off discriminating means and the load constant storing means, the compressor capacity is calculated for each predetermined initial period,
Compressor capacity control means for controlling the capacity of the variable capacity (frequency) compressor based on the calculation result is provided, and when the plurality of indoor units are in operation, the data and the valve initial opening degree are set. The valve opening of each electric expansion valve connected to the operating indoor unit is calculated every predetermined period using the data obtained from the storage means, and the valve opening of the electric expansion valve is controlled based on the calculation result. By providing a valve opening control means for controlling the compressor frequency according to the total required capacity of each room,
Moreover, since the opening degree of each electric expansion valve is determined according to the load of each room, the required capacity can be distributed to the required room, and the comfort can be improved and the energy can be saved.

Further, each indoor unit 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 the indoor temperature setting means and the indoor temperature detecting means set the indoor temperature. A temperature difference calculating means for calculating the temperature difference between the indoor temperature and the indoor temperature is provided, and further capacity determining means for determining the rated capacity of each of the indoor units and determining whether each of the indoor units is operating or stopped. A load that is provided with an on / off determination means, divides the temperature range that the differential temperature can take into a plurality of temperature zones, and determines and stores a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant capacity storage means is provided, and the compressor capacity is calculated every predetermined cycle using data obtained from the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means. Then, compressor capacity control means for controlling the capacity of the capacity (frequency) variable compressor based on the calculation result is provided, and the compressor is connected to each indoor unit for each combination of the number of operating indoor units and the rated capacity. A valve initial opening degree storage means for determining and storing a valve initial opening degree for each electric expansion valve is provided, and when a plurality of indoor units are in operation, the data and the valve initial opening degree storage means are obtained. The valve opening degree of each electric expansion valve connected to the operating indoor unit is calculated every predetermined period using the data of the valve initial opening degree, and the valve opening degree of the electric expansion valve is controlled based on the calculation result. By providing a valve opening control means for controlling the compressor frequency according to the total required capacity of each room and determining the opening of each electric expansion valve according to the load of each room, it is necessary. Capacity can be distributed to the required room, and the valve can be opened initially. The Since determined for each combination of the number of operating units and its rated capacity of the indoor unit, it is capable of capacity control more finely accuracy can be improved and energy saving comfort.

Further, each indoor unit 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 the indoor temperature setting means and the indoor temperature detecting means set the indoor temperature. A temperature difference calculating means for calculating the temperature difference between the indoor temperature and the indoor temperature is provided, and further capacity determining means for determining the rated capacity of each of the indoor units and determining whether each of the indoor units is operating or stopped. A load that is provided with an on / off determination means, divides the temperature range that the differential temperature can take into a plurality of temperature zones, and determines and stores a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant capacity storage means is provided, and the compressor capacity is calculated every predetermined cycle using data obtained from the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means Then, compressor capacity control means for controlling the capacity of the capacity (frequency) variable compressor based on the calculation result is provided, and each electric expansion valve connected to each indoor unit by an approximate expression using the data. Is provided with a valve initial opening calculation means for calculating the valve initial opening, and when a plurality of the indoor units are in operation, the data and the data of the valve initial opening obtained from the valve initial opening calculation means. Valve opening control means for calculating the 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. Since the valve initial opening is calculated by an approximate expression for each combination of the number of operating indoor units and their rated capacities, it is possible to perform finer and more precise capacity control, improve comfort and save energy. Can be planned. Further, since the table of the valve initial opening is not required, it is not necessary to increase the capacity of the memory circuit even if the number of combinations of indoor units increases.

Further, a superheat degree detecting means for detecting the superheat degree of the refrigerant sucked into the variable displacement (frequency) type compressor at predetermined intervals is provided, and the electric expansion valve connected to the operating indoor unit is opened. By providing a valve opening degree determining means for determining the degree of change in degree corresponding to the superheat degree data detected by the superheat degree detecting means, and controlling the valve opening degree by the valve opening degree control means,
Since the control is performed so as to maintain the superheat degree of the refrigerant sucked into the compressor at a predetermined value, it is possible to improve comfort and save energy while controlling the refrigeration cycle more finely and optimally.

Further, a superheat degree detecting means for detecting the superheat degree of the refrigerant sucked into the variable displacement (frequency) type compressor at predetermined intervals is provided, and the electric expansion valve connected to the operating indoor unit is opened. By providing a valve opening degree determining means for determining the sum of the degree change amounts corresponding to the superheat degree data detected by the superheat degree detecting means, and controlling the valve opening degree by the valve opening degree control means, Since the control is performed so as to maintain the superheat degree of the refrigerant sucked into the compressor at a predetermined value, it is possible to improve comfort and save energy while controlling the refrigeration cycle more finely and optimally.

Further, there is provided a valve opening degree determining means for determining the total valve opening degree of the electric expansion valve connected to the operating indoor unit in accordance with the compressor capacity calculated by the compressor capacity controlling means, By controlling the valve opening with the valve opening control means,
Since the valve opening degree of the main electric expansion valve is determined according to the compressor frequency, it is possible to improve comfort and save energy while keeping the refrigeration cycle optimal without complicating the configuration.

Further, the discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the variable capacity (frequency) type compressor at every predetermined cycle, and the discharge temperature corresponding to the compressor capacity calculated by the compressor capacity control means. The compressor discharge temperature determining means is provided to determine the amount of change in the valve opening degree of the electric expansion valve connected to the operating indoor unit in accordance with the discharge temperature data detected by the discharge temperature detecting means. By providing a valve opening degree determining means for controlling the valve opening degree by the valve opening degree controlling means,
Since the control is performed so that the compressor discharge temperature is maintained at a predetermined value, it is possible to improve comfort and save energy while controlling the refrigeration cycle more finely and optimally without complicating the configuration.

[Brief description of 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 a superheat degree SH and an opening change amount of an electric expansion valve.

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

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

FIG. 7 is a diagram showing the relationship between the superheat degree SH and the sum of the electric expansion valve change amounts in the fifth embodiment of the multi-room air conditioning system of the present invention.

FIG. 8 is a refrigeration cycle diagram in a fourth embodiment of the multi-room air conditioning system of the present invention.

FIG. 9 is a control block diagram of a compressor frequency and an electric expansion valve opening degree in the embodiment.

FIG. 10 is a relationship diagram between the compressor frequency and the total opening degree of the electric expansion valve in the embodiment.

FIG. 11 is a refrigeration cycle diagram in a sixth embodiment of the multi-room air conditioning system of the present invention.

FIG. 12 is a control block diagram of a compressor frequency and an electric expansion valve opening degree in the embodiment.

FIG. 13 is a relationship diagram between a compressor frequency and a target discharge temperature.

FIG. 14 is a relationship diagram between a discharge temperature difference ΔTdis and an opening change amount of an electric expansion valve.

FIG. 15: Refrigeration cycle diagram of conventional multi-room air conditioning system

FIG. 16 is a diagram showing the relationship between the capacity ratio of the indoor / outdoor unit and the valve opening degree of the electric flow rate control valve in the same system.

[Explanation of symbols]

 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 Auxiliary throttle 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 26 Signal sending circuit 27 Signal receiving circuit 28 Compressor frequency calculation circuit 29 Expansion valve opening calculation circuit 30 Load constant table 31 Valve initial opening table 32 Suction temperature detection circuit 33 Superheat calculation circuit 34 Saturation temperature detection circuit 35 Valve initial opening Table 36 Discharge pipe 37 Discharge temperature sensor 38 Discharge temperature calculation circuit 39 Discharge temperature detection circuit 40 Discharge temperature difference calculation circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Murozono 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masaaki Okabe, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (11)

[Claims] 1. A variable capacity (frequency) compressor, a four-way valve,
A liquid-side branch pipe that is provided with one outdoor unit having an outdoor heat exchanger and a plurality of indoor units having an indoor heat exchanger and branches a liquid-side main pipe through which a refrigerant liquid mainly flows, An electric expansion valve which is provided in the outdoor unit and is connected via a gas side branch pipe that branches a gas side main pipe through which a refrigerant gas mainly flows and which can electrically control the valve opening degree of each of the liquid side branch pipes. A refrigerating cycle is formed by interposing, 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. A temperature difference calculating means for calculating the temperature difference between the set room temperature and the room temperature is provided from the room temperature detecting means, and further, the capacity determining means for determining each rated capacity of the indoor unit and the indoor unit are in operation. Determine if it is stopped or stopped A load that is provided with an on / off determination means, divides the temperature range that the differential temperature can take into a plurality of temperature zones, and determines and stores a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant value storage means is provided, and a valve initial opening degree storage means for determining and storing a valve initial opening degree for each rated capacity of the indoor unit is provided. The differential temperature calculation means, the capacity determination means, the on / off determination means, the load constant Compressor capacity control means for controlling the capacity of the variable capacity (frequency) compressor based on the calculation result is calculated by using the data obtained from the storage means for each predetermined cycle. When a plurality of units are in operation, the valve opening degree of each electric expansion valve connected to the operating indoor unit is used for each predetermined cycle using the data and the data obtained from the valve initial opening degree storage means. And calculate this Multi-room air conditioning system provided with a valve opening control means for controlling the valve opening degree of the electric expansion valve on the basis of the results. 2. For each of the operating indoor units, the load capacity and the load constant corresponding to the current differential temperature and the predetermined value of the load constant are read from the load constant storage means, and the rated capacity is read from the valve initial opening storage means. The corresponding valve initial opening is read, and the product of the reciprocal of the predetermined value of the load constant and the load constant and the valve initial opening is calculated for each indoor unit, and the valve opening of the electric expansion valve connected to each indoor unit is calculated. , The control is performed so as to obtain this product.
The multi-room air conditioning system described. 3. A variable capacity (frequency) compressor, a four-way valve,
A liquid-side branch pipe that is provided with one outdoor unit having an outdoor heat exchanger and a plurality of indoor units having an indoor heat exchanger and branches a liquid-side main pipe through which a refrigerant liquid mainly flows, An electric expansion valve which is provided in the outdoor unit and is connected via a gas side branch pipe that branches a gas side main pipe through which a refrigerant gas mainly flows and which can electrically control the valve opening degree of each of the liquid side branch pipes. A refrigerating cycle is formed by interposing, 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. A temperature difference calculating means for calculating the temperature difference between the set room temperature and the room temperature is provided from the room temperature detecting means, and further, the capacity determining means for determining each rated capacity of the indoor unit and the indoor unit are in operation. Determine if it is stopped or stopped A load that is provided with an on / off determination means, divides the temperature range that the differential temperature can take into a plurality of temperature zones, and determines and stores a load constant corresponding to the indoor load for each temperature zone and for each rated capacity of the indoor unit. A constant capacity storage means is provided, and the compressor capacity is calculated for each predetermined cycle using data obtained from the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means, and based on the calculation result A compressor capacity control means for controlling the capacity of the variable capacity (frequency) type compressor is provided, and a valve initial for each electric expansion valve connected to each indoor unit for each combination of the number of operating indoor units and rated capacity When a plurality of indoor units are in operation, a valve initial opening storage means for determining and storing the opening is provided, and when the plurality of indoor units are in operation, the data and the valve initial opening data obtained from the valve initial opening storage means are stored. Using a predetermined lap A multi-chamber provided with a valve opening control means for calculating the valve opening of each electric expansion valve connected to the operating indoor unit for each and controlling the valve opening of the electric expansion valve based on the calculation result. Shaped air conditioning system. 4. For each of the operating indoor units, a load constant corresponding to the rated capacity and the current differential temperature and a predetermined value of the load constant are read out from the load constant storing means, and the operation is performed from the valve initial opening degree storing means. The valve initial opening corresponding to the combination of the number of indoor units and rated capacity is read out, the product of the reciprocal of the predetermined value of the load constant and the load constant and the valve initial opening is calculated for each indoor unit, and connected to each indoor unit. The valve opening of the electric expansion valve
The multi-room air conditioning system according to claim 3, which is controlled so as to obtain this product. 5. A variable capacity (frequency) type compressor, a four-way valve,
An outdoor heat exchanger, a single outdoor unit having an electrically valve-controllable main electric expansion valve, and a plurality of indoor units having an indoor heat exchanger are provided in the outdoor unit to mainly provide a refrigerant liquid. Is provided in the outdoor unit and a liquid-side branch pipe that branches the liquid-side main pipe, and the gas-side main pipe in which the refrigerant gas mainly flows is connected via the branched gas-side branch pipe, and each of the liquid-side branch pipes is electrically connected. A room for setting a desired indoor temperature in each of the indoor units and an indoor temperature detecting means for detecting the indoor temperature by forming a refrigeration cycle by interposing an electric expansion valve whose valve opening can be controlled A temperature detecting means is provided, and a temperature difference calculating means for calculating the temperature difference between the set room temperature and the room temperature is provided from the room temperature setting means and the room temperature detecting means, and the rated capacity of each indoor unit is determined. Capacity determining means and that of the indoor unit An on / off discriminating means for discriminating whether the vehicle is operating or stopped is provided, the temperature range in which the differential temperature can be taken is divided into a plurality of temperature zones, and an indoor load is set for each temperature zone and for each rated capacity of the indoor unit. A load constant storage means for determining and storing a load constant corresponding to is provided, and compression is performed at predetermined intervals using data obtained from the differential temperature calculation means, the capacity determination means, the on / off determination means, and the load constant storage means. A compressor capacity control means for calculating the machine capacity and controlling the capacity of the variable capacity (frequency) type compressor based on the calculation result is provided, and is connected to each indoor unit by an approximate expression using the data. A valve initial opening degree calculating means for calculating the valve initial opening degree for each electric expansion valve is provided, and when a plurality of the indoor units are in operation, the data and the valve initial opening degree obtained from the valve initial opening degree calculating means are provided. Opening day Valve opening control means for calculating the 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. A multi-room air conditioning system equipped with. 6. For each of the operating indoor units, the load constant corresponding to the rated capacity and the current differential temperature and a predetermined value of the load constant are read from the load constant storing means, and the valve initial opening degree calculating means operates The initial valve opening is calculated using the data of the number of indoor units and rated capacity, and the product of the reciprocal of the specified load constant, the load constant, and the initial valve opening is calculated for each indoor unit, and connected to each indoor unit. The multi-room air conditioning system according to claim 5, wherein the valve opening of the electric expansion valve is controlled so as to be the product. 7. For each of the operating indoor units, a load constant corresponding to the rated capacity and the current differential temperature and a predetermined value of the load constant are read from the load constant storage means, and the valve initial opening calculation means reads the load constant and the load constant. Calculate the initial valve opening using the number of indoor units in operation and rated capacity data,
A product of a reciprocal of a predetermined value of a load constant, a load constant, and a valve initial opening is calculated for each indoor unit, and the valve opening of the electric expansion valve connected to each indoor unit is controlled to be this product. Item 5. The multi-room air conditioning system according to item 5. 8. A superheat degree detecting means for detecting the superheat degree of the refrigerant sucked into the variable displacement (frequency) type compressor at predetermined intervals is provided, and the superheat degree data detected by the superheat degree detecting means is handled. A valve opening degree determining means for determining the valve opening degree changing amount of the electric expansion valve connected to the operating indoor unit is provided, and the valve opening degree controlling means changes the valve opening degree by a predetermined opening degree. The multi-room air conditioning system according to any one of claims 1 to 7, which is controlled. 9. A superheat detecting means for detecting the superheat of the refrigerant sucked into the variable capacity (frequency) compressor every predetermined cycle is provided, and the superheat detecting means responds to the superheat data detected by the superheat detecting means. A valve opening determining means for determining the sum of the valve opening changing amounts of the electric expansion valve connected to the operating indoor unit is provided, and the valve opening controlling means controls the sum of the valve opening changing amounts and The multi-chamber air conditioning system according to any one of claims 1 to 7, wherein each expansion valve is controlled according to a ratio of valve opening degrees. 10. A valve opening total sum determination means for determining a total sum of valve openings of an electric expansion valve connected to an operating indoor unit in correspondence with a compressor capacity calculated by a compressor capacity control means, 8. The multi-chamber air conditioning system according to claim 1, wherein the valve opening control means determines and controls each valve opening based on the ratio of the sum of the valve openings and each valve opening. 11. A discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the variable capacity (frequency) compressor at every predetermined cycle, and a discharge temperature corresponding to the compressor capacity calculated by the compressor capacity control means. A compressor discharge temperature determining means is provided to determine the valve opening change amount of the electric expansion valve connected to the operating indoor unit in accordance with the discharge temperature data detected by the discharge temperature detecting means. A multi-chamber air conditioning system according to any one of claims 1 to 7, further comprising valve opening change amount determining means for controlling the valve opening degree.