JP3195991B2 - 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 type 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 (hereinafter simply referred to as an expansion valve) or a stop valve. Related to air conditioning systems.

[0002]

2. Description of the Related Art Conventionally, in a multi-room air conditioning system of this type, a capillary tube having a fixed throttle amount is provided in a liquid-side refrigerant pipe of a refrigeration cycle. Also, the aperture amount is constant.

[0003] A conventional multi-room air conditioning system will be described below with reference to FIG. FIG. 7 is a refrigeration cycle diagram of a conventional multi-room air conditioning system.

[0004] As shown in the figure, a multi-room air conditioning system has a plurality of units (two in the prior art example) in one outdoor unit 21.
) Indoor units 22a and 22b. The refrigeration cycle passes through the compressor 23, the four-way valve 24, the outdoor heat exchanger 25, and the receiver 26, which are incorporated in the outdoor unit 21, and connects the liquid-side refrigerant pipe 27 to the indoor unit 22.
a, 22b, the liquid-side refrigerant pipe 28
a and 28b are provided with cooling expansion mechanisms (capillary tubes) 29a and 29b and heating expansion mechanisms 30a and 30b, respectively. The refrigerant pipes 28a and 28b are connected to the indoor heat exchangers 31a and 31a of the indoor units 22a and 22b, respectively. 31b
Connected to. The gas-side refrigerant pipes 32a and 32b from the indoor heat exchangers 31a and 31b join the refrigerant pipe 33, and are connected to the compressor 23 via the four-way valve 24. The heating expansion mechanism 30a, 30b is a capillary tube 34.
a, 34b, and the capillary tube 34
a and 34b are provided respectively to bypass the check valves 35a and 35b.
Is provided.

In this multi-room air conditioning system, during the heating operation, the four-way valve 24 is set to the heating side, and the refrigerant discharged from the compressor 23 passes through the four-way valve 24 to the indoor heat exchangers 31a and 31b. After being used for heating and condensed here, it is adiabatically expanded in the capillary tubes 34a, 34b and the cooling expansion mechanisms 29a, 29b, flows to the outdoor heat exchanger 25, evaporates, and is compressed through the four-way valve 24. Machine 23.

[0006]

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

That is, in the heating operation, in each room where the indoor unit is installed, even when the heating capacity is not required at the time of the thermo-off and the stop,
The refrigerant flows to the unnecessary indoor heat exchanger, which causes a decrease in energy efficiency during the heating operation and a decrease in comfort due to an increase in room temperature.

As one method for reducing the refrigerant pool in such an indoor heat exchanger, as disclosed in Japanese Patent Application Laid-Open No. 1-75860, an expansion valve is used for an expansion mechanism to perform valve opening control according to a load, and to perform heating. It is known that an indoor unit that is stopped during operation is corrected to a valve opening that is larger than a valve opening once determined at predetermined time intervals.

In order to solve the above-mentioned problems, the present invention provides a heating system.
During operation, the thermo-off state and stop
The degree of opening of the electric expansion valve corresponding to the indoor unit
Valve opening control means to be set according to the rated capacity of
With the provision, the object is to reduce the refrigerant pool and improve the energy efficiency.

[0010]

In order to achieve the above object, a multi-room air conditioning system according to the present invention comprises an outdoor unit having a variable frequency compressor, an outdoor heat exchanger, and an indoor heat exchanger. A plurality of indoor units having a liquid-side branch pipe provided in the outdoor unit and branching a liquid-side main pipe through which a refrigerant liquid mainly flows, and the gas-side main pipe through which a refrigerant gas mainly flows are provided in the outdoor unit. A refrigeration cycle is configured by connecting via a branched gas-side branch pipe, and interposing an electric expansion valve capable of electrically controlling the valve opening in each of the liquid-side branch pipes .
If the thermostat is off and the room is stopped
The degree of opening of the electric expansion valve corresponding to the indoor unit
A valve opening control means that is set according to the magnitude of the force is provided.

Further, having a saturation temperature detecting means for detecting the saturation temperature of the chamber within the heat exchanger to each of the indoor unit, the detection
When the saturated temperature reaches the specified value, the thermo-off state
And the degree of opening of the electric expansion valve corresponding to the stopped indoor unit
Is set according to the rated capacity of the indoor unit.
It is provided with a sea urchin valve opening control means.

Further, a pressure detecting means for detecting the pressure in the chamber within the heat exchanger to the respective indoor units, pressure the detected
When the value reaches the specified value, the thermo-off state and stop
The opening degree of the electric expansion valve corresponding to the indoor unit of
A valve opening control means is provided which is set in accordance with the rated capacity of the machine .

[0013]

[0014]

According to the present invention, in the above configuration, when a plurality of indoor units are in the heating operation, when the temperature exceeds the setting of the indoor temperature setting means and the thermostat is turned off and stopped, the rated capacity of the stopped indoor unit is increased. By controlling the opening degree of the expansion valve according to the above, the refrigerant pool of the indoor heat exchanger can be reduced, and the energy efficiency can be improved.

Further, during the heating operation , heat exchange of the indoor unit is performed.
When the saturation temperature detected by the
The electric expansion valve corresponding to the OFF state and the stopped indoor unit
By controlling the opening in accordance with the magnitude of the rated capacity of the indoor unit, the refrigerant pool of the indoor heat exchanger is reduced and energy efficiency is improved.

Further, during the heating operation , heat exchange of the indoor unit is performed.
Thermo-off when the pressure detected by the
The degree of opening of the electric expansion valve corresponding to the state and the stopped indoor unit
Is controlled according to the magnitude of the rated capacity of the indoor unit, thereby reducing the refrigerant pool of the indoor heat exchanger and improving the energy efficiency.

[0017]

[0018]

【Example】

Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

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

As shown in FIG. 1, a 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 are provided in the outdoor unit 1. Indoor heat exchangers 6a and 6b are provided in the units 2a and 2b, respectively. The outdoor unit 1 and the indoor units 2a, 2b
Is connected by liquid side branch pipes 8a, 8b branched from the liquid side main pipe 7 provided inside the outdoor unit 1 and gas side branch pipes 10a, 10b branched from the gas side main pipe 9 provided inside the outdoor unit 1. ing. The liquid side branch pipes 8a, 8b are provided with expansion valves 11a, 11b, respectively, whose valve opening can be pulse-controlled by using a stepping motor, and a receiver 12 capable of storing a refrigerant liquid is provided on the liquid side main pipe 7. And the receiver 12
It is further connected to the compressor 3 via an outdoor heat exchanger 4, a four-way valve 5, and a suction pipe 13. Each of the indoor units 2a and 2b has room temperature detecting means 14a and 14b 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, room temperature, and operation and stop. Are provided.

The cold flowing through the indoor heat exchangers 2a and 2b
Saturation temperature detection means 16a, 16 for detecting the saturation temperature of the medium
b is provided. Further, the indoor heat exchangers 2a, 2b
Pressure detecting means 17a and 17b for detecting the pressure of the pressure sensor are provided.

In this refrigeration cycle, during heating, the refrigerant discharged from the compressor 3 switches the four-way valve 5 to branch from the gas-side main pipe 9 to the gas-side branch pipes 10a and 10b, and the indoor heat exchangers 6a and 6b. 6b, and is condensed and liquefied, and the pressure is reduced by the expansion valves 11a, 11b on the liquid side branch pipes 8a, 8b.
A part of the refrigerant is stored in the receiver 12, and the rest flows through the outdoor heat exchanger 4, evaporates, passes through the four-way valve 5, and is sucked into the compressor 3 again through the suction pipe 13. Has become.

The operation of the above configuration will be described. FIG. 2 is a flowchart showing a first embodiment of the present invention. First, the heating operation is started, the opening degrees of the expansion valves 11a and 11b are set to initial set values A ₀ and B ₀ , and then the indoor temperature setting means is set. 15a,
15b, the room temperatures T _A0 and T _B0 are set. First, it is determined that the operation of the indoor unit 2a is stopped.
a capability rank, that is, setting change to opening A ₁ of the expansion valve 11a according to the magnitude of the rated capacity. If the indoor unit 2a is operating, the temperature T _A1 detected by the indoor temperature detection means 14a is compared with the initial set value T _A0 , and if the detected indoor temperature T _A1 is higher than the set value T _A0 , sets changing the opening of the expansion valve 11a to a _1. Indoor detected temperature T _A1
Is lower than _TA0 , normal operation is performed. Expansion valve 11
a is set to the optimum degree of opening in accordance with the load between the opening A ₀ to A _max. Further determines the operation stop for the indoor unit 2b, if stopped, the ability rank of the indoor unit 2b, sand
That is, the opening degree B _{1 of} the expansion valve 11b according to the magnitude of the rated capacity.
Change the setting to. If the indoor unit 2b is operating, the temperature T _B1 detected by the indoor temperature detecting means 14b is compared with the initial set value T _B0 , and if the indoor detected temperature T _B1 is higher than the set value T _B0 , sets changing the opening of the expansion valve 11b to B _1. When the detected indoor temperature T _B1 is lower than T _B0 , normal operation is performed. Expansion valve 11b is B _max from opening B ₀
The opening is set to an optimum value according to the load up to the time. By such control, the refrigerant pool can be reduced when the heating is turned off and stopped, and the energy efficiency can be improved.

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to FIGS.

FIG. 3 is a flowchart showing a second embodiment of the present invention. First, a heating operation is started and expansion valves 11a and 11a are started.
The opening of b is set to the initial set values A ₀ and B ₀ , and then the saturation temperature is set to the initial set values T _A0 and T _B0 . First, the operation stop of the indoor unit 2a is determined, and if it is the operation, the normal operation is performed. Expansion valve 11a is set to the optimum degree of opening in accordance with the load between the opening A ₀ to A _max. If the indoor unit 2a is stopped, comparing determines the temperature T _A1 and the initial value T _A0 detected by the saturation temperature detecting means 16a, when towards T _A1 is higher than the set value T _A0 is the indoor unit 2a ability Rank , ie of rated capacity
The opening of the expansion valve 11a corresponding to the size setting change to A _1. When T _A1 is lower than T _A0 , the set value of the expansion valve 11a is not changed. Further, the operation stop of the indoor unit 2b is determined, and if the operation is performed, the normal operation is performed. Expansion valve 11
b is set to the optimum degree of opening in accordance with the load between the opening B ₀ to B _max. If the indoor unit 2b is stopped, the temperature T _B1 detected by the saturation temperature detecting means 16b is compared with the initial value T _B0 , and if T _B1 is higher than T _B0 , the performance rank of the indoor unit 2b , that is, setting changing the opening of the expansion valve 11b corresponding to the magnitude of the rated capacity in B _1. When T _B1 is lower than T _B0 , the set value of the expansion valve 11b is not changed. By such control, the refrigerant pool can be reduced when the heating is turned off and stopped, and the energy efficiency can be improved.

(Embodiment 3) Next, a third embodiment of the present invention will be described with reference to FIGS.

FIG. 4 is a flowchart showing a third embodiment of the present invention. First, a heating operation is started and expansion valves 11a and 11a are started.
The opening of b is set to the initial set values A ₀ and B ₀ , and then the pressure of the indoor heat exchanger is set to the initial values P _A0 and P _B0 . First, the operation stop of the indoor unit 2a is determined, and if it is the operation, the normal operation is performed. Expansion valve 11a is set to the optimum degree of opening in accordance with the load between the opening A ₀ to A _max. If the indoor unit 2a is stopped, the pressure P _A1 detected by the pressure detection means 17a is compared with the initial value P _A0 , and if P _A1 is higher than P _A0 , the performance rank of the indoor unit 2a , that is, Large rated capacity
The opening of the expansion valve 11a in accordance with of can set change A _1. When P _A1 is lower than P _A0 , the set value of the expansion valve 11a is not changed. Further, the operation stop of the indoor unit 2b is determined, and if the operation is performed, the normal operation is performed. Expansion valve 11
b is set to the optimum degree of opening in accordance with the load between the opening B ₀ to B _max. If the indoor unit 2b is stopped, the pressure P _B1 detected by the pressure detecting means 17b is compared with the initial value P _B0, and if the P _B1 is higher than P _B0 , the indoor unit 2b
Ability rank, that is, setting change of the opening degree of the expansion valve 11b corresponding to the magnitude of the rated capacity in B _1. P _B1 is P _B0
If it is lower, the set value of the expansion valve 11b is not changed. By such control, the refrigerant pool can be reduced when the heating is turned off and stopped, and the energy efficiency can be improved.

(Embodiment 4) Next, a fourth embodiment of the present invention will be described with reference to FIGS. The same components as those described in the first embodiment are denoted by the same reference numerals.

FIG. 5 shows a fourth embodiment of the present invention.
It is a freeze cycle diagram. This refrigeration cycle is
3 is different from the third embodiment in that the gas side
A stop that electrically opens and closes each of the manifolds 10a and 10b.
That is, stop valves 18a and 18b are provided. Also
FIG. 6 is a flowchart illustrating the present embodiment. First heating
The operation is started, and the opening degrees of the expansion valves 11a and 11b are set to the initial value A.
₀, B₀Set to. Next, stop operation of the indoor unit 2a is determined.
During operation, the stop valve 18a is fully opened and normal operation is performed.
You. The opening degree of the expansion valve 11a is A₀From A_maxLoad up to
Is set to the optimal opening degree according to. When indoor unit 2a stops
If there is, the stop valve 18a is fully closed and the refrigerant is supplied to the indoor heat exchanger 6
Do not pour into a. Furthermore, the operation of the indoor unit 2b is stopped.
If it is an operation, the stop valve 18b is fully opened, and the normal operation is performed.
Roll over. The opening degree B of the expansion valve 11b is ₀From B_maxUntil
The opening is set to an optimum value according to the load. Indoor unit 2b
If stopped, the stop valve 18b is fully closed, and the refrigerant is
So that it does not flow to the exchanger 6b. With such control
Reduces the amount of refrigerant pool during heating thermo-off and shutdown,
Energy efficiency can be improved.

[0030]

As is apparent from the above description, the multi-chamber air conditioning system of the present invention includes a variable frequency compressor, an outdoor
One outdoor unit with heat exchanger and one indoor heat exchanger
A plurality of indoor units, which are provided in the outdoor unit,
A liquid-side branch pipe that branches off a liquid-side main pipe through which air flows, and the outdoor
Machine, and branches off the gas-side main pipe through which the refrigerant gas mainly flows.
Connected through the gas side branch pipe, and that of the liquid side branch pipe
Via electric expansion valves that can electrically control the valve opening
To configure the refrigeration cycle during heating operation.
Corresponding to the indoor unit in the thermo-off state and stopped.
The degree of opening of the motorized expansion valve is determined by the rated capacity of the indoor unit.
Provided with valve opening control means to be set according to
Et al., Reduces the coolant reservoir of the indoor heat exchanger, it is possible to improve the energy efficiency. Further, each of the indoor units is provided with a saturation temperature detecting means for detecting a saturation temperature of the indoor heat exchanger, and when the detected saturation temperature becomes a predetermined value.
Corresponding to the indoor unit in the thermo-off state and the stopped state.
The degree of opening of the motorized expansion valve is determined by the rated capacity of the indoor unit.
Therefore, the refrigerant pool of the indoor heat exchanger can be reduced, and the energy efficiency can be improved.

Further, pressure in the respective indoor units, a pressure detecting means for detecting the pressure of the indoor heat exchanger provided that the detected
When the force reaches the specified value, thermo-off state and stopping
The opening degree of the electric expansion valve corresponding to the indoor unit of
Since it is set according to the magnitude of the rated capacity of the unit, it is possible to reduce the pool of refrigerant in the indoor heat exchanger and improve energy efficiency.

[0032]

[Brief description of the drawings]

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

FIG. 2 is a flowchart according to the first embodiment.

FIG. 3 is a flowchart according to a second embodiment of the present invention;

FIG. 4 is a flowchart according to a third embodiment of the present invention.

FIG. 5 is a refrigeration cycle diagram in a fourth embodiment of the multi-room air conditioning system of the present invention.

FIG. 6 is a flowchart according to the fourth embodiment.

FIG. 7 is a refrigeration cycle diagram of a conventional multi-chamber air conditioning system.

[Explanation of symbols]

 Reference Signs List 1 outdoor unit 2a, 2b indoor unit 3 variable frequency compressor 4 outdoor heat exchanger 6a, 6b indoor heat exchanger 7 liquid side main pipe 8a, 8b liquid side branch pipe 9 gas side main pipe 10a, 10b gas side branch pipe 11a, 11b Expansion valve 14a, 14b Indoor temperature detecting means 15a, 15b Indoor temperature setting means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-95342 (JP, A) JP-A-4-64849 (JP, A) JP-A-63-169451 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) F24F 11/02 102 F25B 13/00 F25B 13/00 104

Claims (3)

(57) [Claims] 1. An outdoor unit having a variable frequency compressor and 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 branched from a liquid-side main pipe and the outdoor unit are provided,
A gas-side main pipe through which a refrigerant gas mainly flows is connected via a branched gas-side branch pipe, and each of the liquid-side branch pipes is provided with an electric expansion valve capable of electrically controlling a valve opening to freeze the liquid. A cycle is being performed and heating is being performed.
Electric expansion valve corresponding to the indoor unit in the off state and the stopped state
Of the indoor unit is set according to the rated capacity of the indoor unit.
Multi-chamber air conditioning system provided with a valve opening control means . 2. A has a saturation temperature detecting means for detecting the saturation temperature of the indoor heat exchanger to each of the indoor unit, and the detection
When the saturation temperature reaches a predetermined value, the thermo-off state and the
The opening degree of the electric expansion valve corresponding to the indoor unit during stop and stop,
Set according to the rated capacity of the indoor unit
The multi-room air conditioning system according to claim 1. Wherein each of the indoor units has a pressure detecting means for detecting a pressure of the indoor heat exchanger, the pressure was the detected Tokoro
When set to a fixed value, the thermo-off state and before stopping
The degree of opening of the electric expansion valve corresponding to the indoor unit
Claim 1 set according to the magnitude of the rated capacity.
The multi-room air conditioning system as described.