JPH0719629A - Air conditioning apparatus - Google Patents

Abstract

PURPOSE:To reduce a power source capacity by driving stepping motors of a plurality of electronic expansion valves by deviating phases of exciting timings of the motors to an example in which the number of phases is reduce simultaneously. CONSTITUTION:The air conditioner comprises a first outdoor electronic expansion valve 15)75 having a 4-phase stepping motor to control a refrigerant amount to be supplied to a first outdoor heat exchanger l41A, a second outdoor electronic expansion valve 151B having a 4-phase stepping motor to control a refrigerant amount to be supplied to a second outdoor heat exchanger 141B, and a controller 161 for controlling entire outdoor units. Phases of exciting timings of the motors of the valves 151A, 151B are deviated to a side in which number of phases to be simultaneously excited is reduced to be driven. The number of phases are reduced simultaneously upon driving, and hence a power source capacity required for exciting can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner (air conditioner; hereinafter referred to as an air conditioner), and more particularly to an electronic air conditioner in which an indoor unit and an outdoor unit are connected by unit piping. The present invention relates to an air conditioner equipped with an expansion valve.

[0002]

2. Description of the Related Art Generally, a plurality of indoor units are arranged in parallel, and a plurality of outdoor units including a compressor, an outdoor heat exchanger, etc. are installed for inter-unit piping connected between the indoor units. A multi-type air conditioner for buildings connected in parallel is known (for example, Japanese Patent Laid-Open No. 2-856).
No. 56).

Since this type of multi-type air conditioner is provided with a plurality of outdoor units, there is an advantage that a large capacity air conditioner system can be easily constructed by combining them.

By the way, in the case of constructing an air conditioner system in which a plurality of outdoor units are combined in this way, there are cases where one outdoor unit has a plurality of outdoor heat exchangers.

This is because, in the case of constructing a heat exchanger having a certain capacity, it is more efficient and controllable to construct the heat exchanger with a plurality of heat exchangers than with one large-capacity heat exchanger. It is because they are winning in the etc.

In these outdoor heat exchangers, for example, during heating, the liquid refrigerant from the condenser (indoor heat exchanger) is decompressed and the flow rate of the refrigerant supplied to each outdoor heat exchanger is adjusted according to the air conditioning (heating) load. An electronic expansion valve is provided for adjustment.
In principle, the electronic expansion valve has a structure in which a needle valve is provided on the rotation shaft of a stepping motor, and the flow rate can be strictly controlled.

Here, the operation when driving a plurality of electronic expansion valves will be described.

FIG. 5 shows a timing chart in the case of performing so-called 1-2 phase excitation to control two electronic expansion valves. In this case, each electronic expansion valve is provided with a four-phase stepping motor, each phase of the first electronic expansion valve is A to D, and each phase of the second electronic expansion valve is A'to. D '.

As shown in FIG. 4, the excitation pattern of the electronic expansion valve has eight patterns of pattern numbers 0 to 7, the circle (◯) indicates that the phase is in the ON state, and the cross mark (×) indicates the corresponding phase. It indicates that the phase is off. In addition, C phase is A
The phase is the inversion state, and the D phase is the B phase inversion state. The excitation pattern of the second electronic expansion valve is the same as the excitation pattern of the first electronic expansion valve.

In the following description, the case of opening two electronic expansion valves will be described.

First, assuming that the excitation is started at the time t ₀ with the excitation pattern 7, the A phase, the A'phase, the D phase and the D'phase are in the ON state, and the other phases are in the OFF state. The load at this time, that is, the power supply capacity required for excitation is "4" when the load required for one-phase excitation is "1".

Next, at time t ₁ , the excitation pattern shifts to the excitation pattern 0, the A phase and the A ′ phase remain unchanged and the other phases are turned off. Similarly, the load at this time is "2" when the load required for one-phase excitation is "1".

Further, at time t ₂ , the excitation pattern 0 shifts to the excitation pattern 1 and the A phase, A'phase, B phase and B'phase are turned on and the other phases are turned off. The load at this time is "4" in the same manner.

Next, at the time t ₃ , when the excitation pattern shifts to the excitation pattern 2, the B phase and the B ′ phase remain unchanged and the other phases are turned off. Similarly, the load at this time is "2" when the load required for one-phase excitation is "1".

In the same manner, each time the excitation pattern is switched, that is, every time the stepping motor drive clock cycle is changed, the load is changed to “4” → “2” → “4” → “2” → ... .

[0016]

Therefore, when the two electronic expansion valves are combined at a timing such as time t ₀ , t ₂ , t _4, etc., four-phase excitation is performed, and the capacity of the power supply is reduced. Must have a capacity capable of four-phase excitation. That is, if attention is paid to individual electronic expansion valves, maximum two-phase excitation is achieved, but there is a problem that a power supply capacity capable of four-phase excitation is required in order to drive two electronic expansion valves at the same time. there were.

That is, in the above conventional air conditioner, when simultaneously controlling a plurality of electronic expansion valves, there is a problem that a power source having a capacity proportional to the number of them must be provided.

Therefore, an object of the present invention is to provide an air conditioner capable of reducing the power supply capacity when operating a plurality of heat exchangers using a plurality of electronic expansion valves.

[0019]

In order to solve the above-mentioned problems, the present invention has a plurality of heat exchangers, and a plurality of electronic expansion valves for adjusting the amount of refrigerant supplied to each heat exchanger. In the air conditioner for driving these electronic expansion valves by a stepping motor, the phase of the excitation timing of the stepping motors of the plurality of electronic expansion valves is reduced to the side where the number of phases to be excited decreases. Each of them is provided with a control means that is driven while being displaced.

[0020]

According to the present invention, the electronic expansion valve regulates the amount of refrigerant supplied to the heat exchanger to which the expansion valve is connected.

At this time, the control means drives by shifting the phases of the excitation timings of the stepping motors of the plurality of electronic expansion valves to the side where the number of phases to be simultaneously excited decreases.

Therefore, the number of phases to be excited is reduced at the same time, and the power supply capacity required for excitation can be reduced.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described with reference to the drawings.

FIG. 1 shows a schematic block diagram of an air conditioner system having a plurality of outdoor units.

The air conditioner system is roughly divided into two outdoor units 1 ₁ and 1 ₂ , two indoor units 3 ₁ and 3 ₂ and inter-unit piping described later.

The outdoor unit 1 _1, the accumulator 10 for the refrigerant of a liquid state refrigerant and a gas state (gas state) to separate returns only gaseous refrigerant to the compressor which will be described later
₁ , a constant capacity compressor A, a variable capacity compressor B whose capacity can be variably controlled according to the air conditioning load in the room, the compressor A,
Oil separator 1 for separating lubricating oil in the refrigerant discharged from B
2 ₁ , a four-way valve 13 ₁ for switching the flow path of the refrigerant, a first outdoor heat exchanger 14 _1A , a second outdoor heat exchanger 14 _1B , a four-phase stepping motor, and a first outdoor heat exchanger 14 _A first outdoor electronic expansion valve 15 _1A for controlling the amount of refrigerant supplied to _1A, and a second outdoor electronic expansion valve equipped with a four-phase stepping motor and for controlling the amount of refrigerant supplied to the second outdoor heat exchanger 14 _1B 15 _1B and a controller 16 _1B for controlling the entire outdoor unit.

Further, the outdoor unit ₁₁ includes an oil separator 12
And a closing valve 23 ₁ for opening and closing the return pipe 21 ₁ and return pipe 21 ₁ for returning the lubricating oil separated by _1.

In this case, the constant capacity compressor A and the variable capacity compressor B are provided as the compressors in order to smoothly control the air conditioning load from zero load to the maximum load.

Similarly, the outdoor unit 1 ₂ includes an accumulator 10 ₂ , a constant capacity compressor C, and an oil separator 1
2 ₂ , four-way valve 13 ₂ , first outdoor heat exchanger 14 _2A ,
A second outdoor heat exchanger 14 _2B , a first outdoor electronic expansion valve 15 _2A having a 4-phase stepping motor, and a second outdoor electronic expansion valve 15 similarly having a 4-phase stepping motor
_2B and a controller 16 ₂ .

Furthermore the outdoor unit 1 _2, the oil separator 12
And a switch valve 23 ₂ for opening and closing the return pipe 21 ₂ and the return pipe 21 ₂ for returning the lubricating oil separated by _2.

Return pipe 21 ₁ and return pipe 2 of the outdoor unit
1 _2, when the imbalance of the lubricating oil amount between the compressors of the outdoor units occurs, the balance pipe for guiding the lubricant oil from the lubricating oil a large amount of compressor lubricant less amount of compressor 5
1 is connected.

The indoor unit 3 ₁ includes an indoor heat exchanger 34 ₁ for exchanging heat with the room, an indoor electronic expansion valve 35 ₁ for controlling the amount of refrigerant supplied to the indoor heat exchanger 34 ₁ .
It is configured with.

[0033] Similarly, the indoor unit 3 _2, indoor and an indoor heat exchanger 34 ₂ for performing heat exchange, the indoor electronic expansion valve 35 for controlling the amount of refrigerant supplied to the indoor heat exchanger 34 _{2 2} And are provided.

The outdoor unit 1 ₁ ,
1 ₂ and the indoor units 3 ₁ and 3 ₂ are connected in parallel, and are configured to include a gas pipe 5 serving as a flow path for a refrigerant in a gas state and a liquid pipe 7 serving as a flow path for a refrigerant in a liquid state. .

[0035] Here, the operation when driving by 1-2 phase excitation two electronic expansion valve by focusing on the outdoor unit 1 _1. In the following description, the case of driving the first electronic expansion valve will be described with reference to the operation flowchart of FIG.

The controller is the first electronic expansion valve 15 _1A.
It is determined whether or not (in FIG. 2, the motor-operated valve 1) is operated (driven) (step S1).

[0037] When operating the first electronic expansion valve 15 _1A, the controller followed by a second electronic expansion valve (FIG. 2
The inside of the motor-operated valve 2) is operated (step S2).

If the second electronic expansion valve is not in operation, the first electronic expansion valve 15 _1A is immediately operated (step S4), and the process is terminated.

When the second electronic expansion valve is in operation, whether the first electronic expansion valve _151A and the excitation pattern number of the second electronic expansion valve are both even numbers or both odd numbers. It is determined whether or not there is a possibility that both will be two-phase excitation at a certain timing and four-phase excitation in total (step S3).

When there is a possibility of four-phase excitation, that is,
When the excitation pattern numbers of the first electronic expansion valve _151A and the second electronic expansion valve are both even numbers or both are odd numbers, the first electronic interrupting the operation of the formula expansion valve 15 _1A (step S5).

When there is no possibility of four-phase excitation, the first electronic expansion valve 15 _1A is operated (step S4), and the process is terminated.

By performing the above-described processing, the maximum three-phase excitation can be achieved, and the power supply capacity can be reduced to 3/4.

Next, a more specific operation will be described with reference to FIG.

FIG. 3 is a timing chart for controlling two electronic expansion valves by performing 1-2 phase excitation.

In this case, the first electronic expansion valve 15
A~D each phase _1A, each phase of the second electric expansion valve 15 _1B and a'-d '.

As shown in FIG. 4, the excitation patterns of the first electronic expansion valve 15 _1A and the second electronic expansion valve 15 _1B are eight patterns of pattern numbers 0 to 7, and the circles (○) indicate the corresponding patterns. The phase is in the on state, and the cross mark (x) indicates that the phase is in the off state.

First, at time t ₀ , the first electronic expansion valve 15 _1A
When the excitation is started with the excitation pattern 7, the controller excites the second electronic expansion valve 15 _1B with the excitation pattern 6.

As a result, the A phase, the D phase and the D'phase are turned on, and the other phases are turned off. The load at this time, that is, the power supply capacity required for excitation is "3" when the load required for one-phase excitation is "1".

Next, at time t ₁ , the excitation pattern of the first electronic expansion valve 15 _1A shifts to the excitation pattern 0 and the second
The excitation pattern of the electronic expansion valve 15 _1B is the excitation pattern 7.

As a result, the A phase, the A'phase and the D'phase are turned on, and the other phases are turned off. Load at this time, the load required to excitation likewise one phase in the case of the time t ₀ When "1" becomes "3".

Further, at time t ₂ , the excitation pattern of the first electronic expansion valve 15 _1A shifts from the excitation pattern 0 to the excitation pattern 1, and the excitation pattern of the second electronic expansion valve 15 _1B excites from the excitation pattern 7. Move to pattern 0, A
The phase, the B phase, and the A ′ phase are turned on, and the other phases are turned off. The load at this time is "3" in the same manner.

Next, at time t ₃ , when the excitation pattern of the first electronic expansion valve 15 _1A shifts to the excitation pattern 2,
The excitation pattern of the second electronic expansion valve _151B shifts to the excitation pattern 1, and the B phase, A'phase and B'phase are turned on, and the other phases are turned off. Similarly, the load at this time is "3" when the load required for one-phase excitation is "1".

Thereafter, similarly, even if the excitation pattern is switched, the load remains constant at "3", that is, always in the three-phase excitation state.

Therefore, the power supply capacity corresponds to the load "3", which is 3/4 of the capacity of the conventional power supply capacity.

Although the above embodiments have been described with respect to the electronic expansion valve having the 4-phase stepping motor, the power source capacity is also the same when the electronic expansion valve having the N-phase stepping motor (N: an integer of 2 or more) is used. Can be reduced.

[0056]

According to the present invention, the electronic expansion valve adjusts the supply amount of the refrigerant to the heat exchanger to which the expansion valve is connected, and the control means controls the stepping motor of the plurality of electronic expansion valves. Since the phase of excitation timing is shifted to the side where the number of phases to be excited at the same time decreases, the number of phases to be excited at the same time decreases, and the power capacity required for excitation can be reduced. The volume required for the device can be reduced, and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing an air conditioner of an embodiment.

FIG. 2 is an operation flowchart of the embodiment.

FIG. 3 is an operation timing chart of the embodiment.

FIG. 4 is a diagram illustrating an excitation pattern.

FIG. 5 is an operation timing chart of a conventional example.

[Explanation of symbols]

 1 outdoor unit 10 accumulator A constant capacity compressor B variable capacity compressor C constant capacity compressor 12 oil separator 13 four-way valve 14 first outdoor heat exchanger 14 second outdoor heat exchanger 15 first outdoor electronic expansion valve 15 Second outdoor electronic expansion valve 16 Controller 21 Return pipe 23 Open / close valve 5 Gas pipe 7 Liquid pipe

Claims (1)

[Claims] 1. A plurality of heat exchangers, a plurality of electronic expansion valves for adjusting the amount of refrigerant supplied to each heat exchanger, respectively, are provided, and these electronic expansion valves are driven by a stepping motor. In the air conditioner to be performed, a control means for driving the plurality of electronic expansion valves by shifting the phases of the excitation timings of the stepping motors to the side where the number of phases to be excited simultaneously decreases is provided. Air conditioner.